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Crop wild relatives (CWRs) have provided breeders with several 'game-changing' traits or genes that have boosted crop resilience and global agricultural production. Advances in breeding and genomics have accelerated the identification of valuable CWRs for use in crop improvement. The enhanced genetic diversity of breeding pools carrying optimum combinations of favorable alleles for targeted crop-growing regions is crucial to sustain genetic gain. In parallel, growing sequence information on wild genomes in combination with precise gene-editing tools provide a fast-track route to transform CWRs into ideal future crops. Data-informed germplasm collection and management strategies together with adequate policy support will be equally important to improve access to CWRs and their sustainable use to meet food and nutrition security targets.

Special Issue: Feeding the World: The Future of Plant Breeding Asymmetry of investment in crop research leads to knowledge gaps and lostopportunities to accelerate genetic gain through identifying new sources andcombinations of traits and alleles. On the basis of consultation with scientistsfrom most major seed companies, we identified several research areas withthree common features: (i) relatively underrepresented in the literature; (ii) highprobability of boosting productivity in a wide range of crops and environments;and (iii) could be researched in‘precompetitive’space, leveraging previousknowledge, and thereby improving models that guide crop breeding and man-agement decisions. Areas identified included research into hormones, recombi-nation, respiration, roots, and source–sink, which, along with new opportunitiesin phenomics, genomics, and bioinformatics, make it more feasible to explorecrop genetic resources and improve breeding strategies. The authors acknowledge the following scientists for helping to achieve a consensus on research bottlenecks with significant implications for crop improvement: Yann Manes (Syngenta), Jeremy Derory (Limagrain), Bruno Marty (BASF), and Hans Braun (recent director of the Global Wheat Program, CIMMYT). We acknowledge Renee Lafitte (Bill and Melinda Gates Foundation) for helpful feedback on the manuscript and Fatima Escalante for valuable assistance in coordinating edits to the manuscript and its formatting. M.R. acknowledges the International Wheat Yield Partnership (https://iwyp.org/) for establishing a precedent of integrating different research strands in wheat for targeted prebreeding and the Foundation for Food and Agricultural Research (https://foundationfar.org/) for supporting a translational research and prebreeding pipeline at CIMMYT to identify and stack climate resilience traits in wheat.

An increase in the rate of crop improvement is essential for achieving sustained food production and other needs of ever-increasing population. Genomic selection (GS) is a potential breeding tool that has been successfully employed in animal breeding and is being incorporated into plant breeding. GS promises accelerated breeding cycles through a rapid selection of superior genotypes. Numerous empirical and simulation studies on GS and realized impacts on improvement in the crop yields are recently being reported. For a holistic understanding of the technology, we briefly discuss the concept of genetic gain, GS methodology, its current status, advantages of GS over other breeding methods, prediction models, and the factors controlling prediction accuracy in GS. Also, integration of speed breeding and other novel technologies viz. high throughput genotyping and phenotyping technologies for enhancing the efficiency and pace of GS, followed by its prospective applications in varietal development programs is reviewed.

Breeding a bitch with two different sires during a single estrous cycle has the potential to facilitate rapid genetic gain and improve reproductive performance within a canine breeding colony. There is limited data regarding the factors that contribute to the success of dual-sired litters in domestic dogs, and only anecdotal evidence suggesting that these litters rarely produce offspring from more than one sire. The objective of this prospective clinical study was to investigate multiple factors that likely affect the success of dual-sired litters on whelping rate, litter size and parentage ratio. These factors include: timing of artificial insemination (AI), order of sires, number of AI's per cycle, semen type, sperm quality and age of sire and bitch. Data collected over a 10 year period from twenty-nine estrous cycles (28 individual bitches of 10 different breeds) were evaluated after an initial AI with frozen semen from the 'genetically desired' sire and followed up with a second AI with either fresh (n = 9) or frozen (n = 16) semen or natural mating (n = 4) from a different, 'back up', sire. DNA parentage of each pup born was determined by using a primary panel of 288 SNPs. The whelping rate and litter size from previous single sire inseminations per estrous cycle, in the same bitches, (n = 16) over 25 estrous cycles using either fresh (n = 4) or frozen-thawed (n = 21) semen, were analyzed as controls. Of the 29 dual-sired breedings, 26 bitches whelped (89.7%), and 8 litters (30.8%) were of mixed parentage. In the litters of mixed parentage after a dual-sired breeding, a greater proportion of the offspring were from the second sire than the first sire (73.0% and 27.0% respectively; P 0.05). Interestingly, in litters where all pups were of single sire parentage after a dual-sired breeding, 50.0% of the offspring were by the first sire and 50.0% were by the second sire. For litters of mixed or single paternity produced by dual-sired breeding there was no difference in average litter size. However, on a per estrous cycle basis for each bitch the whelping rate (89.7% v. 76.0%.) and litter size (5.5 ± 2.5 v. 4.0 ± 2.78) of all dual-sired breedings were greater (P 0.05) compared to previous single-sired breedings (controls) respectively. This study demonstrates that offspring of mixed parentage derived from dual-sired breedings may be achieved. Furthermore, insemination with semen from two different sires may increase the whelping rate and litter size, which is an important consideration when using genetically valuable, or older individuals with potentially reduced fertility.

Crop genetic improvements catalysed population growth, which in turn has increased the pressure for food security. We need to produce 70% more food to meet the demands of 9.5 billion people by 2050. Climate changes have posed challenges for global food supply, while the narrow genetic base of elite crop cultivars has further limited our capacity to increase genetic gain through conventional breeding. The effective utilization of genetic resources in germplasm collections for crop improvement is crucial to increasing genetic gain to address challenges in the global food supply. Genomic selection (GS) uses genome-wide markers and phenotype information from observed populations to establish associations, followed by genome-wide markers to predict phenotypic values in test populations. Characterizing an extensive germplasm collection can serve a dual purpose in GS, as a reference population for predicting model, and mining desirable genetic variants for incorporation into elite cultivars. New technologies, such as high-throughput genotyping and phenotyping, machine learning, and gene editing, have great potential to contribute to genome-assisted breeding. Breeding programmes integrating germplasm characterization, GS and emerging technologies offer promise for accelerating the development of cultivars with improved yield and enhanced resistance and tolerance to biotic and abiotic stresses. Finally, scientifically informed regulations on new breeding technologies, and increased sharing of genetic resources, genomic data, and bioinformatics expertise between developed and developing economies will be the key to meeting the challenges of the rapidly changing climate and increased demand for food.

Vorderwald cattle are a regional cattle breed from the Black Forest in south western Germany. In recent decades, commercial breeds have been introgressed to upgrade the breed in performance traits. On one hand, native genetic diversity of the breed should be conserved. On the other hand, moderate rates of genetic gain are needed to satisfy breeders to keep the breed. These goals are antagonistic, since the native proportion of the gene pool is negatively correlated to performance traits and the carriers of introgressed alleles are less related to the population. Thus, a standard Optimum Contribution Selection (OCS) approach would lead to reinforced selection on migrant contributions (MC). Our objective was the development of strategies for practical implementation of an OCS approach to manage the MC and native genetic diversity of regional breeds. Additionally, we examined the organisational efforts and the financial impacts on the breeding scheme of Vorderwald cattle. We chose the advanced Optimum Contribution Selection (aOCS) to manage the breed in stochastic simulations based on real pedigree data. In addition to standard OCS approaches, aOCS facilitates the management of the MC and the rate of inbreeding at native alleles. We examined two aOCS strategies. Both strategies maximised genetic gain, while strategy (I) conserved the MC in the breeding population and strategy (II) reduced the MC at a predefined annual rate. These two approaches were combined with one of three flows of replacement of sires (FoR strategies). Additionally, we compared breeding costs to clarify about the financial impact of implementing aOCS in a young sire breeding scheme. According to our results, conserving the MC in the population led to significantly (P < 0.01) higher genetic gain (1.16 ± 0.13 points/year) than reducing the MC (0.88 ± 0.10 points/year). In simulation scenarios that conserved the MC, the final value of MC was 57.6% ± 0.004, while being constraint to 58.2%. However, reducing the MC is only partially feasible based on pedigree data. Additionally, this study proves that the classical rate of inbreeding can be managed by constraining only the rate of inbreeding at native alleles within the aOCS approach. The financial comparison of the different breeding schemes proved the feasibility of implementing aOCS in Vorderwald cattle. Implementing the modelled breeding scheme would reduce costs by 1.1% compared with the actual scheme. Reduced costs were underpinned by additional genetic gain in superior simulation scenarios compared to expected genetic gain in reality (+4.85%).

Reproductive traits have a major influence on the economic effectiveness of horse breeding. However, there is little information available. We evaluated the use of reproductive traits as selection criteria in official breeding programs to increase the reproductive efficiency of breeding studs, analysing 696 690 records from the pedigree data of eight Spanish horse populations, with different breeding purposes. The reproductive parameters studied in both sexes were age at first foaling (AFF), age at last foaling, average reproductive life and generational interval. In the females, the average interval between foaling (AIF) and interval between first and second foaling were also studied. There were clear differences between sexes and breeds, which may be due to management practices, breeding purposes and the status of the populations, rather than to differences in actual physiological conditions. Riding mares were the most precocious (AFF, 1937.64 to 2255.69 days) and had a more intensive reproductive use (AIF, 625.83 to 760.07 days), whereas sires used for meat production were the most precocious males (AFF, 1789.93 to 1999.75 days), although they had a shorter reproductive life (1564.34 to 1797.32 days). Heritabilities (0.02 to 0.42 in females and 0.04 to 0.28 in males) evidenced the genetic component of the reproductive traits, with Sport Horses having the higher average values. These results support the selection by AFF to improve reproductive aspects because of its medium–high heritability and its positive correlations with other important reproductive traits. The inclusion of the AIF is also recommended in sport populations, because this determines the length of the breaks between foaling and conditions the reproductive performance of the dams, as well as their selective intensity, genetic gain and genetic improvement. It is therefore an important economic parameter in breeding studs. Fil: Gómez, M. D.. Universidad de Sevilla; España Fil: Sánchez, M. J.. Universidad de Sevilla; España Fil: Bartolomé, E.. Universidad de Sevilla; España Fil: Cervantes, I.. Universidad Complutense de Madrid; España Fil: Poyato Bonilla, J.. Universidad de Sevilla; España Fil: Demyda Peyrás, Sebastián. Universidad de Córdoba; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina Fil: Valera, M.. Universidad de Sevilla; España

The aim of the study was to examine the variation and breeding effects on the stay-green traits, and to identify the relationship between the different growing seasons and grain yield of the Pannonian winter wheat. The experiment was carried out with a historical set of 25 winter wheat cultivars during four growing seasons, in a typical Pannonian location at the experimental field of the Institute of Field and Vegetable Crops, Novi Sad, Serbia. The results demonstrated a linear wheat grain yield progress at the rate of 45.7 kg ha−1 yr−1, along with significant variations observed in most stay-green traits due to increased capability of modern wheat cultivars to retain prolonged crop greenness. Furthermore, significant positive correlations between the onset and mid senescence and grain yield in three out of four studied seasons showed that the prolonged senescence led to grain yield increase. Modern wheat cultivars showed an increase of crop greenness at anthesis, onset and mid senescence, and the stay-green interval, as well as a faster senescence rate. Moreover, the stay-green interval was positively correlated with grain yield in each growing season, while the senescence rate was significantly positively correlated with grain yield in the three growing seasons. Furthermore, all examined traits, except the endpoint of senescence (N10), were significantly negatively correlated with anthesis time during all growing seasons. Knowledge about the positive correlations between the prolonged stay-green traits and grain yield could be used for adjusting post-anthesis senescence traits and implemented in winter wheat breeding programs under the climate conditions of the Pannonian Plain. This is the accepted peer-reviewed version of the published manuscript [http://fiver.ifvcns.rs/handle/123456789/2993] available after 5 August 2024.

On station small ruminant researches in Ethiopia were ineffective due to various factors. As alternative, community based breeding program (CBBP) has emerged. In the current CBBPs, sires’ side selection only (SN1) was practiced. The objective of the present work was to compare SN1 by simulating alternative breeding scenarios for Abergelle (AB), Centeral Highland (CH) and Woyto-Guji (WG) goat breeds in Ethiopia. Three scenarios including selection on dam’s side (SN2) in addition to SN1, application of genomic selection (SN3) on SN1 and use of sires from SN1 for mating in additional flocks (SN4) were simulated and compared with SN1 based on the predicted annual genetic gain (PAGG) and discounted profits. The breeding objective traits or selection criteria were six month weight (6mw, kg) for all breeds, average daily milk yield (ADM, kg) and survival to six month of age (SURV) for AB, litter size at birth (LSB) for CH and WG, litter size at weaning (LSW) for CH and kidding interval (KI, days) for WG. ZPLAN + software was used for the simulation. The PAGG for 6mw ranged from 0.086 kg (SN4) to 0.249 kg (SN3) for AB where it ranged from 0.471 kg (SN4) to 0.970 kg (SN3) for ADM for same breed. PAGG ranging from 0.130 kg (SN4) to 0.467 kg (SN3) and from 0.204 kg (SN4) to 0.311 kg (SN3) for CH Gonder and Ambo sites, respectively were simulated whereas this parameter ranged from 0.103 kg (SN4) to 0.271 kg (SN3) for WG. The alternative breeding scenarios to SN1 resulted in better PAGGs, especially for 6mw in three of the goat breeds and for ADM in AB. Based on the PAGGs and profitability we recommend SN2 over SN1. However, SN4 could also be applied, compared to SN1, in view of better profitability and suitability of addressing emerging demands.

Switchgrass (Panicum virgatum L.) is a biomass candidate crop which has been improved for yield, but disease resistance development has largely been ignored. Bipolaris oryzae (Breda de Haan) Shoemaker can cause Bipolaris seed rot, reducing seedling establishment, and Bipolaris leaf spot, reducing biomass yield. In order to initiate a breeding program, heritability based on half-sib progenies of the disease resistance were conducted in 47 half-sib progenies of lowland ‘Kanlow’ and upland ‘Cave-in-Rock’. Test crosses of progenies from resistant and susceptible parents in upland ‘Shelter’ and Cave-in-Rock were conducted to determine genetic control of resistance to Bipolaris leaf spot. To breed for resistance to two diseases, two cycles of recurrent phenotypic selection were done separately in Shelter and Cave-in-Rock at 10% selection intensity. As a result, resistance to Bipolaris seed rot showed moderate to high heritability (0.33 ± 0.16 to 0.83 ± 0.09) in both individual- and half-sib-based computations, reflecting actual genetic gain (44.5–125.3%) from two cycles of selections. However, resistance to Bipolaris leaf spot showed non-significant heritability (0.02 ± 0.06 to 0.19 ± 0.19) and non-significant progress of selection for the trait. Results from test crosses suggested that the resistance was not controlled by R genes but possibly was quantitatively inherited by many alleles with small effects. Such a difference in the gains resulted in non-significant correlation between two resistances. Due to high progress in selection resistance to Bipolaris seed rot, the screening method for resistance can be integrated to existing breeding programs.

Improved genetic, genomic and statistical technologies have increased the capacity to enrich breeding populations for key alleles underpinning adaptation and continued genetic gain. In turn, directed genomic selection together with increased heritability will reduce genetic variance to narrow the genetic base in many crop breeding programs. Diverse genetic resources (GR), including wild and weedy relatives, landraces and reconstituted synthetics, have potential to contribute novel alleles for key traits. Targeted trait identification may also identify genetic diversity in addressing new challenges including the need for modified root architecture, greater nutrient-use efficiency, and adaptation to warmer air and soil temperatures forecast with climate change. Yet while core collections and other GR sources have historically been invaluable for major gene control of disease and subsoil constraints, the mining of genetically (and phenotypically) complex traits in GR remains a significant challenge owing to reduced fertility, limited seed quantities and poor adaptation through linkage drag with undesirable alleles. High-throughput field phenomics (HTFP) offers the opportunity to capture phenotypically complex variation underpinning adaptation in traditional phenotypic selection or statistics-based breeding programs. Targeted HTFP will permit the reliable phenotyping of greater numbers of GR-derived breeding lines using smaller plot sizes and at earlier stages of population development to reduce the duration of breeding cycles and the loss of potentially important alleles with linkage drag. Two key opportunities are highlighted for use of HTFP in selection among GR-derived wheat breeding lines for greater biomass and stomatal conductance through canopy temperature.

The interactions between nitrogen (N) and water are manifold, and the concept of co-limitation provides a quantitative framework for integration. This paper tested the hypothesis that selection for yield increased water-N co-limitation in wheat adapted to winter rainfall environments of Australia. To test this hypothesis, we measured evapotranspiration, N uptake and yield in a historic collection of varieties released between 1958 and 2007 (exp. 1) and between 1969 and 2015 (exp. 2). Crops were grown under 5 (exp. 1) or 4 (exp. 2) environmental conditions resulting from the combination of sites, seasons, and supply of N and water. Genetic gain of yield, i.e. the slope of the regression between yield and year of release was 14–24 kg ha−1 y−1 or 0.36–0.52% y−1. This yield gain was associated with a linear increase in water-N co-limitation, in turn associated with an increase in N uptake per mm of evapotranspiration at a rate of 0.0019 kg N mm−1 y−1. Our findings highlight the critical role of nitrogen for the adaptation of wheat to low rainfall environments, and the scope for further yield improvement based on traits that integrate resources.

Heritability has been proven as an effective means for assessing the genetic variation harbored in populations of aquaculture species. In order to make an overall genetic evaluation, heritabilities of twelve traits in red swamp crayfish, Procambarus clarkii (5 months old), including growth, body dimension and processing traits, were estimated in this study. The estimation was based on the additive-dominance genetic analysis model using the incomplete diallel cross between three geographic populations of the species under two rearing environments. Results indicated that all heritabilities for mature females (n = 1312) and males (n = 1109) were low to medium in magnitude (P

This study presents results of selection response to Streptococcosis agalactiae (SA) resistance in a commercial stock of red tilapia (Oreochromis spp.) after one generation of selection. Families were produced from 93 males and 128 females using a nested design (1 male: 2 females). At 60 days post-hatch, 30 fish from each family were challenged by intraperitoneal injection of bacterial solution (SA strain AQSA01) at the 96 h LD50 concentration (1 × 109 CFU mL−1) and observed for 14 days. Disease-resistance was measured as a binary trait (dead/alive) and as survival time, or the number of days from challenge initiation until death. Animal and sire-dam models were applied with body weight fitted as a covariate, whereas tank and generation were treated as fixed effects. Data from 128 full-sib and 35 half-sib families was used to estimate variance components using ASREML version 4.1. Heritability estimates for the base generation (G0) were highest, 0.25 ± 0.12 for binary data on the liability scale and 0.20 ± 0.08 for days until death. Breeding candidates in G0, selected from the top 10 high-ranking families based on their estimated breeding values (EBVs), were used to produce 25 full- and six half-sib families. When data from G0 and G1 were combined, heritability estimates were 0.29 ± 0.11 and 0.27 ± 0.08 for threshold sire-dam and animal models, respectively. The realized genetic gain was 2.53 days for survival time, equivalent to about a 58% improvement from 4.3 days in the base generation. In terms of binary response, the probability that the G1 fish survived to the end of challenge period increased 10% from the base generation. This study demonstrates a significant selection potential for increased disease-resistance to S. agalactiae in red tilapia.

Six groups of Norway spruce (Picea abies L. Karst) plants with varying levels of genetic gain and unimproved local provenances were compared in four realised gain trials at four sites in central Sweden. The groups were planted separately in experimental plots and compared in terms of survival rate and height 4 years after planting, as well as survival rate, height, diameter and areal volume production 13–16 years after planting. The genetically improved groups all produced higher volumes than the unimproved local provenances, and the clonal bulk of 23 full-sib families’ volume production per unit area was 56% higher than that of local provenances. The genetic groups followed expected levels of genetic gain, except for individual clones (which varied substantially in performance) and full-sib families. There were greater relative differences between local provenances and genetic groups in areal volume production 13–16 years after planting than in height at 4 years after planting. The results confirm that growth of improved genetic groups is largely consistent with expected values of realized genetic gain. They also indicate that clonal mixes rather than one or a few clones should be deployed in clonal forestry. The comparison of early measured height with areal production showed that early height measurements are good indicators of realized genetic gain and differences in areal production are greater than early differences in height.

Applying successive high selection pressures in fecund aquatic animals can easily lead to high increases in inbreeding and, consequently, to reductions in fitness and long-term genetic progress. The Pacific oyster Crassostrea gigas is one of the most commercially important aquaculture species worldwide. C. gigas from three cultured stocks in China, Japan and Korea were used to establish three mass-selected strains for fast growth, and a positive response to selection for fast growth was observed in the first two generations of these strains. To determine whether continuous progress can be achieved by selection for growth, we evaluated response to selection for the eighth to tenth generations of the three breeding strains. At grow-out stage, a genetic gain of 8.8–15.2%, selection response of 0.506–0.786 and realized heritability of 0.275–0.420 for shell height were observed in the selective breeding strains after seven to nine generations of selection. For body weight of oysters at grow-out stage, an average of 8.12–12.47% in genetic gains and 0.358–0.706 in selection responses were also obtained in the three mass-selected strains. The current response to selection for growth obtained in the eighth- to tenth-generation selection strains suggests that a large amount of genetic variance still remains in the selected strains and there is a potential for sustained genetic improvement in growth-related traits in these strains through selective breeding. The results obtained in this study provides important information for future breeding programmes for C. gigas.

peer-reviewed In the absence of informative health and welfare phenotypes, breeding for reduced animal mortality could improve overall health and welfare, provided genetic variability in animal mortality exists. The objective of the present study was to estimate genetic (and other) variance components for animal mortality in pasture-based, seasonal-calving dairy and beef herds across multiple life stages as well as to quantify the genetic relationship in mortality among life stages. National mortality records were available for all cattle born in the Republic of Ireland. Cattle were grouped into three life stages based on age (0 to 30 days, 31 to 365 days, 366 to 1095 days) whereas females with ≥1 calving event were also grouped into five life stages, based on parity number (1, 2, 3, 4, and 5), considering both the initial 60 days of lactation and a cow's entire lactation period, separately. The mean mortality prevalence ranged from 0.70 to 5.79% in young animals and from 0.53 to 3.86% in cows. Variance components and genetic correlations were estimated using linear mixed models using 21,637 to 100,993 records. Where heritability estimates were different from zero, direct heritability estimates for mortality in young animals (≤1095 days) ranged from 0.006 to 0.040, whereas the genetic standard deviation ranged from 0.015 to 0.034. The contribution of a maternal genetic effect to mortality in young animals was evident up to 30 days of age in dairy herds, but this was only the case in preliminary analysis of stillbirths in beef herds. Based on the estimated genetic standard deviation in the present study, the incidence of mortality in young animals could be reduced through breeding by up to 3.4 percentage units per generation. For cows, direct heritability estimates for mortality, where different from zero, ranged from 0.003 to 0.049. The genetic standard deviation for mortality in cows ranged from 0.005 to 0.016 during the initial 60 days of lactation and ranged from 0.011 to 0.032 during the cow's entire lactation. Genetic correlations among the age groups as well as between the age groups and cow parities had high standard errors. Genetic correlations among the cow parities were moderate to strongly positive (ranging from 0.66 to 0.99) and mostly different from zero. Results from the present study can be used to inform genetic evaluations for mortality in young animals and in cows as well as the potential genetic gain achievable.

Many local breeds have become endangered due to their substitution by high-yielding breeds. To conserve local breeds, effective development strategies need to be investigated. The aim of this study was to explore conservation and development strategies based on quantified strengths, weaknesses, opportunities and threats (SWOT) for two local cattle breeds from Northern Germany, namely the German Angler (GA) and Red Dual-Purpose cattle (RDP). The data comprised 158 questionnaires regarding both breeds’ SWOT, which were answered by 78 farmers of GA and 80 farmers of RDP. First, data were analysed using the SWOT-Analytic Hierarchy Process (AHP) method, which combines the qualitative strategic decision tool of SWOT analysis and the quantitative tool of AHP. Second, prioritised SWOT factors were discussed with stakeholders in order to form final conservation and development strategies at breed level. For GA prioritised strengths were daily gain, meat quality, milk production and the usage of new biotechnologies, weaknesses were genetic gain in milk production and inbreeding, opportunities were organic farming and breed-specific characteristics and threats were milk prices and dependency regarding the dairy business. Consequently, three conservation and development strategies were formed: (1) changing relative weights and the relevant breeding goal to drift from milk to meat, (2) increasing genetic gain and control the rate of inbreeding by the implementation of specific selection programs and (3) selection of unique and breed characteristic components on product level, that is, milk-fat and fine muscle fibers. For RDP defined strengths were robustness, high adaptability for different housing systems and a balanced dual-purpose of milk and meat, weaknesses were inbreeding, breed extinction, genomic selection with young bulls and milk yield, opportunities were organic farming and dual-purpose aspects and threats were milk and decreasing beef cattle prices. Thus, three conservation and development strategies were identified: (1) adjust relative weights and the relevant breeding goal to balance milk and meat yield, (2) increasing genetic gain and avoid extinction by implementing targeted selection programs and (3) selection of unique and breed characteristic traits on breed level, that is, environmental robustness. Quantified SWOT establish a basis for the exploration of conservation and development strategies at breed level. Explored strategies are promising even if the stakeholder approach was limited for small populations regarding a small number of stakeholder groups. The used approach reflects farmers’ individual convenience better than existing quantitative strategy decision tools on their own.

Barramundi (Lates calcarifer) is a tropical species of increasing aquaculture interest. In efforts to accumulate genetic gains through selection, the species is now subject to several pedigree-based breeding programs globally; however, these breeding programs would further benefit from the implementation of genomic selection methodologies. Here we make genomic predictions for polygenic growth and body shape traits and compare expected genetic gains from genomic selection across several breeding strategies to those expected from pedigree-based on-farm selective breeding programs. A commercial scale cohort of barramundi (24 half-sib families) was grow-out at two farm locations, a brackish-water pond-based system in Queensland, and a freshwater recirculating aquaculture system (RAS) in Victoria. A total of 2139 fish were genotyped using a custom 70 k Axiom™ myDesign™ SNP array (ThermoFisher Scientific™) and phenotyped at harvest for whole fish weight (WFW), standard fish length (SL), body depth (BD), Fulton's condition factor (K) and body shape index (BS). Fillet weight (FW) was also recorded on a subset of Victorian fish. Heritabilities based on genomic relationships were estimated across barramundi from both farm sites for WFW (0.33 ± 0.06 to 0.35 ± 0.04), SL (0.27 ± 0.05 to 0.35 ± 0.04), BD (0.29 ± 0.06 to 0.30 ± 0.04), and K (0.14 ± 0.04 to 0.21 ± 0.04), and for FW (0.35 ± 0.16) in the Victorian site only. Genotype-by-environment interactions were also detected for all traits (GBLUP rg between locations ranging from 0.41 for K to 0.61 for SL). To optomise the design of a breeding program using genomic information, three possible genomic selection strategies were explored: MULTIPLE, separate breeding programs at each farm site; GENERAL, a single breeding program using the general effects from an interaction model; and SINGLE, a single breeding program based on the performance of individuals within one main farm site. The accuracy of GBLUP breeding value prediction for the WFW, SL and BD traits was higher than PBLUP for all scenarios (10–33% and 15–49% improved prediction accuracy in the Victoria and Queensland environments, respectively). Estimates of genetic gain were also consistently higher when GBLUP was applied (19–31% for WFW in VIC) compared to PBLUP (14–23% for WFW in VIC). Under the SINGLE scenario, genetic gains for the target farm site were the same as for MULTIPLE, but only 48–66% of the MULTIPLE gains were predicted for the non-target farm site. In comparison, GENERAL, which operates at half the cost of MULTIPLE, achieved 72–97% of the expected gains of MULTIPLE across farm sites, suggesting that it would be the most appropriate scenario for genomic selection in the production environments evaluated.

A severe outbreak of infectious salmon anemia (ISA) virus in Chile in 2007 led to considerable changes in breeding practices and regulations for the salmon industry. The Atlantic salmon (Salmo salar) broodstock reproductive cycle, from birth to maturity, is now wholly carried out in freshwater in some companies while commercial salmon are finished in saltwater. The genetic differences pertaining to growth between fish reared in freshwater and seawater are unknown. The objective of this work was to evaluate the genotype by environment interaction for body weight in two independent Atlantic salmon populations (year class 2012 and 2014), both reared in seawater and freshwater. Heritability estimates and genetic correlations for body weight in both environments were estimated through a linear bivariate animal model. Estimated heritabilities were moderate to high (0.23 ± 0.04 to 0.46 ± 0.08); indicating that body weight improvement is feasible through genetic selection. The genetic correlations for body weight between freshwater and saltwater rearing were low: 0.31 ± 0.13 for year class 2012 and 0.26 ± 0.14 for year class 2014; indicating a considerable genotype by environment interaction for growth in Atlantic salmon. The genotype by environment interaction causes a re-ranking of selection candidates, reducing the potential to maximize genetic gain for growth when broodstock is reared in freshwater and production is done in seawater.

Selective breeding refers to the selection of individuals or populations with superior genetic traits from a population or family, for the purpose of directionally screening and enriching the dominant traits of the target species, to acquire breeds with directional dominant traits. The mandarin fish (Siniperca chuatsi) is an important high-quality freshwater fish widely cultured in China. The selective breeding of this species to obtain desirable growth performance traits has garnered considerable attention by researchers. We constructed a basic breeding population by selecting high growth as the target trait. Subsequently, we conducted family selection through four successive generations. We used the growth data (initial and harvest body weights) of the four generations of mandarin fish to estimate the realized heritability, selection response, and genetic gain, on the body weight of mandarin fish. We obtained the following values from generations F1–F4: realized heritability 0.17–0.47, selection response 0.40–1.12, and genetic gain 6.94–17.25%. The average genetic gain was 12.14%. Moreover, after four generations of breeding, the average growth rate of the selective breeding population had increased by 16.3% compared with that of the control group. This indicated that selective breeding had resulted in good genetic progress regarding the growth traits of mandarin fish and desirable selection effects. The coefficient of variation for the harvest body weight of generations F1–F4 decreased with increasing generation number (18.68–10.10%). This shows that the degree of variation in body weight among families decreased over generations, tending towards genetic stability after selective breeding. Our results provide a scientific basis and technical support for mandarin fish breeding and may serve as a reference for breeding other aquaculture species.

Extending the shelf life of tomatoes is very essential for the reduction of great losses in quality and quantity. Knowledge of genetic architecture of the shelf life contributing traits and their inheritance pattern in different genetic backgrounds is a key issue for the development of high yielding and good shelf life cultivars. An investigation was undertaken to estimate the nature and magnitude of gene action for 18 fruit quality and yield traits governing shelf life through six generations (P1, P2, F1, F2, B1, and B2) mean analysis in the F1, Arka Vikas × Red ball cross. Inadequacy of additive-dominance model in explaining the inheritance of fruit quality traits governing shelf life revealed the significance of joint-scaling test and presence of epistasis. The dominance x dominance interaction was larger than the additive x additive and additive x dominance effects and the dominance component was greater than the additive component. Duplicate epistasis played a greater role than complementary epistasis. Shelf life and its contributing traits such as TSS, lycopene, titratable acidity, pH, ascorbic acid, fruit diameter, fruit firmness, locule number, and yield per plant are controlled by dominant genes with duplicate epistasis. Simple selection procedure in the early segregating generation for shelf life and its contributing traits is ineffective in improving genetic gain as dominance and dominance × dominance gene effects are non-fixable. The additive and dominance components successfully are exploited in the advanced segregating population by evaluating a large number of families. One to two cycles of bi-parental mating followed by intensive selection lead to dissipation of dominance and enhance the frequency of genes with increasing effects on the expression of fruit quality traits governing shelf life. Both additive and dominance with a predominance of dominance effects of genes are important in the inheritance of fruit quality traits governing shelf life.

The Red Maasai are indigenous sheep breeds known for their adaptability in arid and semi-arid environments while the Dorper is known for its good mutton production. A field experiment cross breeding program for the two breeds was set up in 2003 to exploit these traits. In this paper, we present the genetic parameters for birth weight (BWT), weaning weight (WWT) and weight at nine months (MWT) for pure Red Maasai (RRRR), pure Dorper (DDDD), 75% Dorper (DDDR) and 50% Dorper (DDRR) breeds. The genetic parameters were estimated by fitting four different multivariate animal models while ignoring or including maternal effects. The model with the lowest Akaike’s Information Criterion (AIC) was chosen as the best model for the estimation of genetic parameters. The average annual genetic gain of the studied traits for each breed group was estimated by regressing the estimated breeding values on year of birth. Records from 5442 lambs recorded over a period of 17 years (2003-2019) were used in this analysis. The breed group, sex, type of birth, season of birth and age of the dam significantly (P

The increase of litter sizes in conventional weaner production systems in the past 30 years is associated with decreasing piglet birth weights, and in further consequence, with increasing piglet mortality. The aim of this study was the implementation of practicable litter quality recording schemes in six participating organic herds, in order to record new litter quality traits for the estimation of genetic parameters and breeding values. The litter quality traits were “Average Piglet Birth Weight” (ABW), “Litter Evenness” (LE), and “Piglet Vitality” (PV). Litter quality traits were recorded on a scale from 1 to 4, whereas score 4 indicated the desired performance value. A further female fertility trait was the “number of live born piglets” (LBP). The dataset included 2602 recorded litters from 1102 German Landrace x German Large White crossbred sows (rotational crossing system) from the birth years 2007 to 2015. For the estimation of genetic (co)variance components, univariate and bivariate animal models were applied. Heritability estimates for the litter quality traits were 0.09 for LE, 0.14 for PV and 0.21 for ABW. Genetic correlations among litter quality traits were throughout large and favourable, i.e., 0.90 between LE and ABW, 0.90 between LE and PV, and 0.75 between ABW and PV. Genetically, all new litter quality traits were negatively correlated with LBP (genetic antagonistic relationship). Estimated genetic (co)variance components were input parameters in selection index calculations. The aim was the identification of an optimal selection strategy for organic weaner production systems, i.e., an optimised breeding goal for the selection of replacement sows from the own herd. Using a desired gain approach, we focussed on the maximisation in genetic gain for litter quality traits, while keeping the status quo for LBP. The optimal index scenario included the phenotypic information from all four traits from the selection candidate (sow) from two litters. At the same time, three litters from the dam of the sow, and one litter from 10 half sibs, were available as information sources. For such a design of information sources and genetic relationships, optimal economic weights were 7.50 € for LBP and 20 € for all litter quality traits LE, ABW and PV. The correlation between the index and the aggregated genotype from this scenario was 0.60. Genetic gain per year considering a generation interval of 2.80 years for organic weaner production systems was larger than 0.04 points for all litter quality traits.

The Caribbean scallop Argopecten nucleus is a species with a great potential for commercial aquaculture in the Caribbean given its fast growth and the availability of culture technology. However, its production relies completely on hatchery-reared seed, and the survival in early stages, particularly during the settling process, is the main limitation for this activity to become cost effective. Thus, in order to assess the feasibility of improving survival of larvae and post-larvae of A. nucleus through genetic selection without affecting growth, it was estimated the heritability and the genotype-environment interactions for such traits, as well as the genetic correlations between them. These parameters were estimated based on intraclass correlations of 40 full-sib families (10 half-sib families) at 1, 11 and 75 days post fertilization. Heritability values were very high for the post-larvae survival (0.49), while it was low and not significant for larvae survival (≤0.07) and medium to high for growth traits of larvae and post-larvae (>0.3). The traits analyzed in post-larvae exhibited significant genotype-environment interactions in relation to culture depth in the sea. No significant genetic correlations between the measured traits were found. The results suggest the existence of an important genetic component in the variation of post-larval survival, and larval and post-larval growth, as well as a high potential response to direct genetic selection, especially for post-larval survival (50% increase per generation), without affecting the growth traits.

Quantifying historic increases in water-limited potential yield (PYw) achieved through breeding provides insight into associated changes in physiology and can assist with future cultivar improvement. We compared PYw of bread wheat cultivars popular in southern New South Wales released between 1901 and 2014. In both 2015 and 2016, cultivars were sown at multiple sowing dates to allow comparisons to be made at a consistent optimal flowering date (early October), and thus control for the large differences in life cycle duration. Seasonal conditions were close to average in 2015 and extremely favorable in 2016. In both, grain yield increased across the historic period studied at 26 kg/ha per annum, regardless of whether a common sowing date or flowering date was used. Yield gain was not linear, and there was a period of rapid yield increase during the middle of the 20th century, that culminated with the release of semi-dwarf cultivars. Yield gain was relatively slower from the 1980s until the present day, possibly due to selection for grain quality traits (grain size) at the expense of grain number. Historic yield increases were not associated with earlier flowering, but with an interplay between greater grain number/m2 and greater grain weight which was the result of increased partitioning of assimilates to spikes, and greater number of grains per unit spike weight (fruiting efficiency). Greater partitioning to the spike in modern cultivars was associated with reduced dry matter (DM) production prior to flowering. Modern cultivars have a less stable flowering time across sowing dates, and shorter life cycle, but improved partitioning in modern cultivars appeared decoupled from shorter developmental phases prior to flowering. The performance of the novel vernalisation sensitive cultivar Longsword showed that future yield gain may be achieved through the combination of early sowing and slow development, increased DM production and superior partitioning to grain.

In this study were investigated two growth deceleration genetic parameters (gamma and g-ratio) to evaluate alternatives for sire selection for improvements in finishing precocity without promoting changes in adult size. Additionally, were estimated genetic correlations between these parameters and weights (YW: yearling weight, FW: final weight), carcass quality traits at yearling (LMA: loin muscle area, BF: back fat thickness, RF: rump fat thickness) and morphological composition traits at yearling (BS: body structure score, FS: finishing precocity score, MS: muscling score). Both gamma and g-ratio parameters were obtained by genetic evaluation of animals using a random regression model on linear spline polynomials. Subsequently, (co)variances components and genetic parameters were estimated for gamma and g-ratio parameters and other traits, by bivariate analyses through Bayesian method. All evaluated traits showed genetic variability. However, selection of sires for maternal ability may provide a slow genetic gain. For direct additive genetic effect, the weight at 365 days of age is a good indicator of the weight until 700 days of age. The stronger maternal genetic correlation estimated between weights at 120 and 205 days of age (0.99) indicates that only one of these traits would be necessary for maternal ability selection. Gamma parameter presented weak or null genetic correlation with YW, FW, BF, RF, FS, and MS. Genetic correlations between g-ratio and weight indicated that sire selection based on lower values for g-ratio could reduce breeding values for YW and FW. The g-ratio presented a positive and weak correlation with LMA, BF, and RF (ranging from 0.08 ± 0.02 to 0.15 ± 0.02). Weaker genetic correlation was estimated between g-ratio and BS (0.15 ± 0.02) compared to FS and MS (0.23 ± 0.02 and 0.23 ± 0.02, respectively). Gamma and g-ratio parameters are not, individually, satisfactory indicators of finishing precocity when it is assessed using BF, RF, FS, and MS. However, the inclusion of these growth deceleration parameters in selection indices, along with traits related to carcass quality and morphological composition, could be an alternative to gradually modify growth rate and improve body composition in Nelore cattle herds.

Canola is an extremely important commodity to the western Canadian economy. Annual or geographic fluctuations in yield due to heat stress can have a significant influence on total production. To increase the stability of canola yield, breeders need to select for increased heat tolerance in a reliable, repeatable, cost effective manner that represents commercial production conditions. Field experiments with 10 (5 maintainer and 5 restorer) inbreds and the 25 corresponding hybrids were conducted across 2 years with 2 locations per year. Each experiment had two planting dates (normal planting date and a late planting date). The experiments were designed to determine if: 1) planting date can be used as a proxy for heat stress; 2) heterosis can minimize the impact of heat stress; and 3) direct selection within a heat-stress environment improves genetic gain for heat-stress tolerance. Principal component analysis of the Tmax, Tmin, Tmean, soil moisture, daily light integral and yield were conducted. The resulting biplot analyses demonstrate that the temperature variables had a greater impact on yield than soil moisture or daily light integral and therefore planting date was identified as a successful proxy for heat stress. The heat-stress treatment caused a 23% mean reduction in seed yield (20% reduction within the hybrids and 25% reduction within the inbreds) indicating that heterosis can reduce the impact of higher temperatures on canola yield. The mean heat susceptibility index was 0.94 and 1.20 for the hybrids and inbreds respectively; further demonstrating that the hybrids were more heat tolerant than the inbreds. Analyses of the GCA for the inbreds shows 4 cross-over interactions between the two temperature treatments indicating that direct selection for heat tolerance will be necessary to increase the response to selection for this trait. Overall canola breeders interested in increasing heat tolerance need to consider utilizing planting date as a high-temperature treatment and cannot rely on indirect selection from experiments under optimal conditions.

Early height measurement has commonly been used as a selection criterion in the Norway spruce breeding program in Sweden when the main breeding goal is to increase timber production per unit area. The aim of this study was to compare differences in early height with differences in stand yield at the time of the first commercial thinning in improved (IM) and unimproved (UNI) stands of Norway spruce. The study was based on ten field trials established in southern and central Sweden. The results showed that IM material produced, on average, 27.5% more volume per hectare over the first half of the rotation compared with UNI material. The early differences in height measured at an age of between 3 and 6 years were on average 17.7% greater in the IM trees. There was substantial variation in the average volume difference between IM and UNI between the trials, but the number of trials studied renders the results reliable. This study indicates that for improved Norway spruce at the middle of the rotation age growing in southern and central Sweden, volume production per hectare is greater than expected volume predicted from early height measurements.

Acrocomia aculeata [Jacq.] Lodd. ex Martius is an outstanding species to produce biofuels from its fruit oil. This species occurs in small populations and, consequently, inbreeding depression limits its development and jeopardizes its traits, mainly on fruit number (fruit abortion). Thus, this study aimed to estimate inbreeding depression, genetic and population parameters, verify the direct and indirect selection for pulp oil production and model the structured population effect. The data were collected in A. aculeata germplasm collection, referred to 44 half-sib families, and eight out of them had at least one inbred individual. All families were clustered in populations according to their geographic coordinates. The inbreeding depression reduced the fruit number and is one of the causes of fruit abortion. It was more severe in productive traits, indicating they are likely ruled by the dominance effect. The heritabilities were high for most of traits. The genetic gain of pulp oil production was 178% for direct selection, 173% and 171% for indirect selection, considering fruit moist matter and fruit number, respectively. Productive and vegetative traits had a low and high fixation index, respectively. There is evidence of genetic drift for vegetative traits. The model with structured populations obtained high accuracy. A reciprocal recurrent selection is indicated for macaw palm’s genetic breeding. Therefore, this work helps to establish strategies to keep the genetic variability of A. aculeata for a sustainable breeding program and to confirm it as a source of renewable energy and a new oil crop for biofuel production.

The use of sexed semen in dairy and beef cattle production provides a number of benefits at both farm and industry levels. There is an increasing demand for dairy and beef products across the globe, which will necessitate a greater focus on improving production efficiency. In dairy farming, there is surplus production of unwanted male calves. Male dairy calves increase the risk of dystocia compared with heifer calves, and as an unwanted by-product of breeding with conventional semen, they have a low economic value. Incorporating sexed semen into the breeding programme can minimise the number of unwanted male dairy calves and reduce dystocia. Sexed semen can be used to generate herd replacements and additional heifers for herd expansion at a faster rate from within the herd, thereby minimising biosecurity risks associated with bringing in animals from different herds. Furthermore, the use of sexed semen can increase herd genetic gain compared with use of non-sorted semen. In dairy herds, a sustainable breeding strategy could combine usage of sexed semen to generate replacements only, and usage of beef semen on all dams that are not suitable for generating replacements. This results in increased genetic gain in dairy herd, increased value of beef output from the dairy herd, and reduced greenhouse gas emissions from beef. It is important to note, however, that even a small decrease in fertility of sexed semen relative to conventional semen can negate much of the economic benefit. A high fertility sexed semen product has the potential to accelerate herd expansion, minimise waste production, improve animal welfare and increase profitability compared with non-sorted conventional semen.

Selection in native local breeds needs great carefulness due to the small population size and the risk of inbreeding. Furthermore, most breeds are dual-purpose, and milk and beef attitudes are antagonistic. For preservation purposes functional traits need to be considered. Focusing on the small local Rendena cattle, this study aimed to analyse the genetic correlations among milk, beef and udder health traits and the response to selection predicted under different scenarios. The study considered milk, fat and protein yields (MY), factor scores for udder volume (UV), conformation (UC) and muscularity obtained from type traits scored on primiparous cows, and performance test traits (PT) measured on young bulls at test station: average daily gain, in vivo SEUROP fleshiness, in vivo dressing percentage. Somatic cell score (SCS) was considered as a functional trait, with a possibility of restricting its genetic gain to zero. The study considered 281 497 MY test-day data collected on 16 974 cows, and data from linear type evaluation on 11 992 primiparous cows for factor scores. The PT data were recorded on 1428 young bulls, and SCS obtained from cell counts at milk recording. Bi-trait restricted maximum likelihood animal model analyses were performed to assess genetic parameters. Heritability varied from 0.157 (fat) to 0.442 (dressing percentage). Udder volume and MY resulted positively genetically correlated (average correlation 0.427), whereas the low-negative genetic correlation between MY and UC (−0.141) suggested a negative impact of milk gain on udder form. Beef traits of factor muscularity and PT showed medium-high favourable genetic correlations (from 0.357 to 0.984), excluding a null correlation between daily gain and muscularity. The genetic correlation MY v. muscularity was unfavourable (−0.328 on average), whereas null correlations were found in MY v. PT, apart from fat v. dressing percentage (−0.151). Somatic cell score showed low unfavourable correlations with protein (0.111) and UV (0.092), and favourable correlations with UC (−0.193). Response to selection in different scenarios indicated a good balanced gain for milk and beef when standardized economic weights of 0.66 and 0.34 are given to the two attitudes, and SCS genetic gain is restricted. Current genetic trends (MY and PT increasing, but muscularity lessening) reflect a stronger selection for milk, suggesting a slight progressive change towards a milk conformation. Aiming to preserve the dual-purpose characteristics of a breed, proper breeding policies taking into account the genetic relationships among traits and including functional traits should be applied in local dual-purpose populations.

The growth and wood traits of four taxa (a) 42 Casuarina junghuhniana (Cj) families from four natural provenances, (b) 9 second generation (2G) Cj families, (c) 43 Cj clones and (d) 14 C. cunninghamiana families, were evaluated at two contrasting sites in southern India. Survival was high (>90%) at the dry coastal Ongole site at 48 months for both the seedlings and clones. Overall, growth was better at the higher rainfall, irrigated inland location West Godavari (WG), but the clones had 16% lower mean survival than Cj seed sources. C. cunninghamiana had significantly lower survival at both sites at 72 months. The clones had comparable growth (height and diameter at breast height) and better stem form and axis persistence than natural provenances and 2G seedlots of C. junghuhniana. Provenance variation was significant for growth traits, while narrow and broad-sense heritability estimates were low to moderate in C. junghuhniana, suggesting that both recurrent selection and breeding among appropriate provenances and deployment of clones are likely to result in genetic gain. Genotype-by-environment interaction was low for growth traits. Wood (density and pulp yield), fibre, and vessel traits were evaluated from core samples in 9–10 families/clones of each taxon at 48 months. Fibre length was significantly higher in 2G seedlots and clones than natural Cj provenances, while C. cunninghamiana had the longest fibres at the irrigated inland site. C. cunninghamiana had significantly lower wood density and Runkel ratio due to lower fibre wall thickness and wider cell lumen (fibre and vessel). All taxa had higher wood density at the dry coastal site due to higher fibre wall thickness, but vessel wall thickness was higher at the irrigated WG site. Narrow-sense heritability estimates for wood traits were moderate for fibre length and width, but low and imprecisely estimated for pulp yield and other traits. However, the broad-sense heritability (clonal repeatability) estimate was moderate for pulp yield, with low clone-by-site interaction, suggesting deployment of suitable, stable clones would be an appropriate deployment strategy.

Genetic improvement of woody bioenergy crops is essential to maximize the genetic gain of industrially useful products. Conventional selective breeding to improve complex traits is laborious and time-consuming. A molecular marker-assisted selection approach based on multi-omics genetic dissection and pyramiding gene module utilization has not been developed for woody industrial crops. We initially identified 80 correlated genes enriched in co-expression modules that sustainably participate in lignocellulosic biosynthesis during various developmental periods in Populus. Using an adult germplasm population (15 years old, 435 accessions) of Populus tomentosa, we integrated association mapping, expression quantitative trait loci, and epistasis analyses to reveal the pleiotropy of causative genes within the core co-expression modules, such as ALG14, GSL8, SMT1, and IRX15-L.2, that drive natural variations in gene expression and harvested wood traits. We further pyramided two superior haplotypes and one desirable epistatic allele (Hap_01PtoSMT1+Hap_01PtoALG14+SNP2PtoIRX15-L.2) to alleviate linkage drag in multi-trait selection and improve industrial pulpwood products. Early-period selection study and genetic interpretation of the allelic differences of candidate elite trees in a juvenile germplasm population (5 years old, 435 accessions) demonstrated the accuracy and efficiency of our haplotype-based selection method relative to phenotype-based selection. This study provides novel insights into the improvement of industrial wood traits and also facilitates the rational breeding of perennial trees.

8 Pág. Departamento de ​Mejora Genética Animal, A common type of rearing in aquaculture selective breeding programs is to keep families in separate tanks until fish is large enough to be individually tagged. This type of rearing introduces an environmental effect common to the members of the same family which can be difficult to be disentangled from genetic effects when traditional BLUP evaluation is used. The use of genomic evaluation could lead to a better prediction of these effects as markers can capture more accurately genetic relationships between fish raised in different tanks and between full-sibs raised in the same tank. The objective of this simulation study was to predict the benefit of genomic evaluation (GBLUP) when compared to BLUP in the presence of common environmental effects. Models that included or excluded these effects when they were present were compared. Populations with two different levels of linkage disequilibrium were generated. The heritability of the selected trait was 0.4 and three different proportions of phenotypic variance due to common environmental effect (0.0, 0.1 and 0.3) were considered. Nested mating designs where each male was mated to two females were simulated to create 200 full-sib families with 10 or 50 fish per family. GBLUP was less affected than BLUP by the presence of common environmental effects. The loss in genetic gain ranged from 0% to 4% with GBLUP and from 2% to 7% with BLUP. As a consequence, the benefit of GBLUP increased in the presence of common environmental effects, and the extra benefit increased with increasing linkage disequilibrium and family size. In the absence of these effects, genetic gain from GBLUP was up 20% higher than from BLUP and in their presence, genetic gain from GBLUP was 27% higher than from BLUP. Although GBLUP always led to lower inbreeding than BLUP, there were no extra benefits in terms of extra reductions in the presence of common environmental effects. Finally, when these effects were present but ignored in the evaluation model, the loss in genetic gain was moderate but inbreeding increased dramatically, particularly in BLUP scenarios., The research leading to these results has received funding from the Instituto Nacional de Investigacion y Tecnología Agraria y Alimentaria (FPI-SGIT2016-02), the European Union's Seventh Framework Program (KBBE.2013.1.2-10) under grant agreement n◦ 613611, the Ministerio de Ciencia e Innovacion, ´ Spain (grant CGL2016-75904-C2-2-P and PID2020-114426GB-C22) and from the European Commission Horizon 2020 (H2020) Framework Programme through grant agreement no 727315 MedAID project (Mediterranean Aquaculture Integrated Development).

Effects of long term selection for improved growth on traits of commercial interest are generally not well documented in aquaculture species, specifically in giant freshwater prawn (GFP) Macrobrachium rosenbergii. The present study analysed a total of 106,756 data records collected from a pedigreed GFP population over nine years (2007–2015) or nine generations (including base population) to evaluate genetic progress achieved for body weight and to examine correlated genetic changes in measurements of body dimensions (carapace length, abdominal length, carapace width and abdominal width), as well as fitness related traits (early maturity, EM and small blue claw male, SM). Linear mixed model fitting the random effects of individual prawn and common full-sib groups and the fixed effects of generation, line, pond by generation subclass, morphotypes for each sex and a linear covariate of grow-out day was used to analyse growth-related traits, whereas threshold logistic animal model was applied to binary data (EM and SM). The heritabilities were moderate for body weight and measurements of body dimensions (10 to 60%), but the estimates for EM and SM were low (0.13 ± 0.06 and 0.08 ± 0.01, respectively). The proportion of variance explained by the common full-sib effects was only 5–7% for measurements of body traits (weight and body dimensions). Genetic correlations among body traits were high and positive (0.93–0.97). These body traits however showed negative (i.e. favourable) genetic correlations with both EM and SM. Direct genetic gain for body weight and correlated changes in measurements of body dimensions and fitness related traits (EM and SM) were measured as differences in estimated breeding values (EBVs) between the selection line and control group within the same generation. The accumulative genetic gain in body weight after eight generations was 56%, averaging 7% per generation. Selection for high growth, however, did not have detrimental effects on measures of body dimensions and fitness related traits (i.e. EM and SM). In comparison to one of the founder stocks collected from Mekong river, the selection line had 50% greater body weight under the same testing environment in the latest generation 2015. Our findings provide information to refine the current breeding program to simultaneously improve traits of commercial interest in this important aquaculture species M. rosenbergii.

It is particularly important to select the provenance with better adaptability in the context of the counteracting potential adverse effects of climate change. However, the growth environment of trees and the length of breeding cycle determine the uncertainty of early selection. Thereby, it is advisable to provide information for provenance selection by analyzing the relationship between young, middle and mature forests. Chinese fir(Cunninghamia lanceolata (Lamb.) Hook.) is an evergreen coniferous tree species with rapid growth and high-quality timber, and it is an important reforestation and commercial tree species in South China. The provenance experimental forests of Chinese fir in Jiangxi and Guangxi were taken as the test object, the growth survey went by three stages of growth: young, middle and mature ages. The linear mixed model was used to evaluate the differentiation of different forest stage provenances in terms of growth. K-medoids clustering algorithm was used to group provenances, the geographical distribution characteristics of Chinese fir were evaluated based on the major groups, and the risk of early selection and the genetic gain of excellent provenances were calculated. The highest total variability was explained by the genotype effect (G) in the young, middle-aged and mature forest stage, the influence of genotype increased through time, while the influence of site was reduced and the G×E interaction changed in a small range. The differences in heritability were similar between young and middle-aged forests, but the heritability of growth traits was higher at Jiangxi than Guangxi in the mature forest stage. The provenances with excellent productivity Chinese fir showed aggregation distribution at the mature forest stage, and the provenances with worst growth were mainly distributed in the northern marginal production area.

The potential grain yield of maize increased tremendously from the 1980s to 2010s, as did the optimal plant density. However, cultivars were always bred in different environments owing to the varied eras in which they were created. To analyze the effect of genetic improvement on maize grain yield and related traits, we selected six hybrids from different eras for a detailed field study without water and fertilizer stress in 2017 and 2018 at Qitai Farm (89°34′E, 44°12′N), Xinjiang, China. The hybrids were selected based on the highest yields recorded in different years from 300 maize cultivars that had undergone 15 years of field testing. The maximum yield gap was approximately 20 % under the density with maximal yield measured from cultivar SC704 (the oldest cultivar) to DH618 and MC670 (the most recent cultivars) during the two experimental years. The global gain in yield potential was 559.3 kg ha−1 year−1 or 3.4 % with year of release (YOR−1). The genetic gain in grain yield was 111.4 kg ha−1 year−1 (0.62 % YOR−1) during the experimental years. The genetic contribution to potential grain yield was 18.0 %. Further analysis on the genetic progress of phenotypic traits showed that the leaf angle above ear decreased significantly by 0.26° year−1 (1.1 % YOR−1), which optimized the light distribution in the canopy and significantly improved the radiation use efficiency (RUE, 0.0286 g MJ−1 year−1 or 0.9 % YOR−1). The ear ratio decreased significantly by 0.0034 year−1 (0.71 % YOR−1). Other morphological traits did not change significantly with the year of release, indicating that the breeding of maize cultivars from the 1980s to 2010s primarily focused on the leaf angle above ear and ear ratio in phenotype. For the physiological traits, the leaf area duration (LAD) increased by 0.4097 m2·d year−1 (1.1 % YOR−1), and the photosynthetic rate at maturity significantly increased by 0.268 μmol CO2 m−2 s−1 year−1 (3.7 % YOR−1), which finally significantly increased the total biomass by 0.285 Mg ha−1 year−1 (0.96 % YOR−1) and harvest index (HI) by 0.0021 year−1 (0.45 % YOR−1). Therefore, 18.0 % of the increased yield potential from the 1980s to 2010s was contributed by breeding under an optimal environment, among which the leaf angle above ear, ear ratio, LAD, photosynthetic capacity at maturity, biomass accumulation and HI played an important role for this genetic contribution.

The objective of this study was to estimate genetic parameters between body weight and morphometric traits to choose selection criteria to improve genetically the body weight and body conformation using Bayesian inference. Body weight, body length, chest girth, croup height, croup width, withers height, and body condition score of 645 Santa Ines meat sheep were used to estimate the genetic parameters in a multi-trait animal model with Bayesian approach. The heritability estimates ranged from 0.19 ± 0.05 to 0.32 ± 0.07 (croup width and body condition score respectively), which allow them to respond to genetic selection. The genetic correlations between body weight and morphometric traits were positive and ranged from 0.18 ± 0.17 to 0.98 ± 0.02. The genetic correlation between body weight and chest girth (0.98 ± 0.02) indicates that selection based on one trait will result in genetic gain for the other. The body weight is the main selection criterion to increase the meat production via genetic selection of the animals due to its moderate heritability and moderate to high genetic correlation with the other traits studied. However, if calibrated electronic scales are not available for the sheep producers, they can use the morphometric measurements to carry out the selection of animals to result in indirect genetic gains for body weight. If the breeders want to choose only one morphometric trait to indirectly improve the genetic body weight, chest girth is recommended due to its extremely high genetic correlation with body weight. The next step would be to develop an index that takes into account all the morphometric measurements to use it as indirect indicator of body weight.

Hair coat traits are used as indicators of animal adaptation because of their importance for thermoregulation and parasites resistance. These traits are evaluated visually based on a score in some beef cattle breeding programs. Data from 38,800 Angus animals were used to compare linear and threshold animal models in order to validate genetic parameters for visual scores of hair coat at weaning (WHC) and yearling (YHC), and conformation (YC), precocity (YP) and muscling (YM) at yearling. The genetic trends for WHC and YHC and their relationships with YC, YP, YM, birth weight (BW), weight gain from birth to weaning (BWG) and from weaning to yearling (YWG), scrotal circumference (SC), and gestation length (GL) were also obtained. For WHC and YHC, higher heritabilities were estimated with the threshold models (0.249±0.039 and 0.295±0.041, respectively) compared to the linear models (0.188±0.029 and 0.218±0.032, respectively). However, similar heritabilities were obtained with the two models for YC, YP and YM. Rank correlations between sire breeding values predicted for WHC and YHC using linear and threshold models ranged from 0.75 to 0.95, considering the top 2 to 50% of the selected sires. For YC, YP and YM, small changes in sire ranking are expected when these models are used (rank correlations higher than 0.86), regardless of the proportion of selected sires. Cross-validation strategies by regression showed that genetic selection for all visual scores will also promote improvements in phenotypic performance. Genetic trends were significant (P

It was reasoned that, incorporating reproductive technologies and genomic selection in the current dairy goats breeding programme would generate higher response to selection compared to use of natural mating in the current conventional breeding programme. This premise was tested by deterministic simulation approach and compared to the current breeding programme where natural mating and conventional breeding programme is used in the tropics. Two breeding schemes with three breeding strategies were simulated. The first scheme was conventional breeding scheme (CS) which represented the current dairy goat-breeding programme in the tropics. An alternative scheme was genomic breeding scheme (GS). Each scheme was evaluated with three mating strategies. They include; conventional scheme using natural mating (CNM), AI-Liquid semen (CLS) and AI-Frozen semen (CFS), and genomic scheme using natural mating (GNM), AI-Liquid semen (GLS) and AI-Frozen semen (GFS) strategies, with 5% of the total population in the nucleus and 95 % in the commercial. The current study found that CLS and GLS were superior compared to CFS and GFS, and CNM and GNM strategies in terms of annual genetic gain, returns and profit per doe per year. The CLS realised additional Kenya Shillings (KES) 3.00 and 3.61, 151.31 and KES 46.72, 148.89 and 47.81, in genetic gain, returns and profitability compared to CNM and CFS, respectively. The CLS incurred low costs KES 23.38 compared to CFS with KES 24.47 but higher than CNM with KES 20.96. On the other hand, CFS strategy has generated additional returns KES 104.59 and profit KES 101.08 but lower by KES 0.61 in genetic gain compared to CNM strategy. Implementation of genomic scheme has generated additional improvement across the three mating strategies in all the parameters measured compared to the conventional scheme. The GS realised additional KES 11.54, 10.80 and 10.21 in genetic gain, KES 161.30, 183.48 and 175.90 returns, and 136.30, 158.48 and 150.90 profit in the GNM, GLS and GFS, respectively, compared to those realised in CNM, CLS and CFS. Genetic gain increased with increased nucleus population size up to 15 % and thereafter, it declines in both CS and GS schemes with optimal nucleus size ranging between 14 % and 16 %. In conclusion, the current study demonstrated that adoption of reproductive technologies such as AI would optimize response to selection in dairy goat breeding programs in the tropics. The response to selection in such breeding programmes could be maximized in combination with genomic selection.

WOS: 000417074400008, Wheat breeders in Turkey have been developing newvarieties since the 1920s, but fewstudies have evaluated the rates of genetic improvement. This study determined wheat genetic gains by evaluating 22 winter/facultative varieties released for rainfed conditions between 1931 and 2006. The studywas conducted at three locations in Turkey during 2008-2012, with a total of 21 test sites. The experimental design was a randomized complete block with four replicates in 2008 and 2009 and three replicates in 2010-2012. Regression analysis was conducted to determine genetic progress over time. Mean yield across all 21 locations was 3.34 t ha(-1), but varied from 1.11 t ha(-1) to 6.02 t ha(-1) and was highly affected by moisture stress. Annual genetic gain was 0.50% compared to Ak-702, or 0.30% compared to the firstmodern landmark varieties. The genetic gains in drought-affected sites were 0.75% compared to Ak-702 and 0.66% compared to the landmark varieties. Modern varieties had both improved yield potential and tolerance to moisture stress. Rht genes and rye translocations were largely absent in the varieties studied. The number of spikes per unit area decreased by 10% over the study period, but grains spike(-1) and 1000-kernel weight increased by 10%. There were no significant increases in harvest index, grain size, or spike fertility, and no significant decrease in quality over time. Future use of Rht genes and rye translocations in breeding programs may increase yield under rainfed conditions. (C) 2017 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license., CRP WHEAT; Turkish Ministry of Food, Agriculture, and LivestockGida Tarim Ve Hayvancilik Bakanligi, The International Winter Wheat Improvement Program is supported by CRP WHEAT and the Turkish Ministry of Food, Agriculture, and Livestock. Molecular markers were identified by Dr. Susanne Dreisigacker at CIMMYT, Mexico. The authors highly appreciate suggestions and technical editorial assistance from Emma Quilligan.

Different breeding strategies targeting two indigenous cattle breeds of Ethiopia (Borana and Horro) were evaluated with the objective of developing appropriate breeding programs that would maximize production and productivity of the breeds maintained on pastures using a deterministic approach. Borana was evaluated for beef, milk and both for beef and milk (dual purpose) while Horro was evaluated for milk and dual purposes. Two units, breeding unit and production unit, consisting of six selection groups were defined for both breeds. Selection criteria used were yearling weight, milk yield, age at first calving, calving interval and calf survival to yearling for dual purpose program and milk yield, age at first calving, calving interval and calf survival to yearling for milk production program. In addition, yearling weight, age at first calving, calving interval and calf survival to yearling were used to improve beef production in Borana breed. Three different levels of breeding bull selection proportions (5%, 10%, and 15%) were used. For all goal traits investigated, more genetic gains were obtained from bull selection groups than the cow selection groups. The bull selection groups also had the shortest generation interval compared to the cow groups (4.07 vs. 6.42 years). From the estimated annual genetic gains for the individual goal traits, all traits had favorable genetic gains except age at first calving. Genetic gains per year were highest for milk yield followed by live weight. Genetic gains were near zero for the other traits. Nearly comparable annual genetic gains were estimated for both Borana and Horro cattle breeds assumed for milk improvement program under different selection proportions. Estimated genetic improvements of about 291.96, 268.63 and 252.73 l of milk were simulated for Borana in 5%, 10% and 15% breeding bull selection proportion. The corresponding improvements for Horro were 291.55, 268.31 and 252.43 l. However, gains were higher in Borana when the two cattle breeds are assumed for dual purpose program (85.92–98.64 for Borana Vs 78.14–90.26 for Horro). Estimated genetic improvements for live weight ranged from 38.96 to 45.11 kg for Borana and 34.17–39.46 kg for Horro when both cattle breeds investigated for dual purpose program. In the current study information is lacking on economic values for each goal trait. Thus, further works are warranted. Except for age at first calving, the genetic gain per year in yearling weight, milk yield, calving interval and survival to yearling obtained from the different options are satisfactory and can result in reasonable genetic improvements of these cattle breeds.

The contribution of animal breeding to changes in animal performance is well documented across a range of species. Once genetic variation in a trait exists, then breeding to improve the characteristics of that trait is possible, if so desired. Considerable genetic variation exists in a range of meat quality attributes across a range of species. The genetic variation that exists for meat quality is as large as observed for most performance traits; thus, within a well-structured breeding program, rapid genetic gain for meat quality could be possible. The rate of genetic gain can be augmented through the integration of DNA-based technologies into the breeding program; such DNA-based technologies should, however, be based on thousands of DNA markers dispersed across the entire genome. Genetic and genomic technologies can also have beneficial impact outside the farm gate as a tool to segregate carcasses or meat cuts based on expected meat quality features.

Basin wildrye (Leymus cinereus [Scribn. & Merr. A. Love]) is a perennial grass native to western regions of North America. Despite its importance for rangelands, stand establishment of basin wildrye is difficult due to its poor seedling vigor. We undertook to increase the seedling vigor of the basin wildrye cultivar “Trailhead” by using selection for emergence from deep seeding depth. We carried out two cycles of selection in two select populations and included two random populations, in which no direct selection occurred. We characterized the indirection effect of the selection on biomass, seed production, and stand percentage in these populations under field conditions. We used amplified fragment length polymorphic (AFLP) markers to identify regions of the genome associated with the selection by identifying allele frequency changes between the base population and the select and random populations. The second cycle select population and the first cycle random population possessed the highest total emergence from deep seeding (60% and 59%, respectively) compared with the base population (26%). The field evaluations showed no differences in genetic variation among the base, select, and random populations for biomass, seed production, and stand percentage. On the basis of the analysis of the AFLP markers, diversity increased slightly among the random populations and decreased slightly among the select populations. In the select populations, band frequencies increased for aggcac403, actcag185, and aggcac208. The band frequencies of aggctg212 and actctc66 decreased in both random and selected cycles. The results indicate that targeted selection for trait improvement in this native grass can be successfully completed with minimal effect on population genetic diversity.

The purpose of this study was to estimate the genetic parameters and to evaluate whether performance results of young horses are good predictors for later sport performance, in order to propose alternative selection strategies to assess adult show jumping (SJ) ability. The data included 84,600 performance records from 4011 Spanish Sport Horses. Two different bivariate animal models with genetic groups were compared, using rankings of young and adult horses as the dependent variables. The models included the age as covariate, and gender, event, type of penalty scale and competition level as fixed effects. The horse*rider interaction and the animal permanent environment random factors were tested to find the most suitable model (A vs B, respectively). The heritability values obtained were in the low range, between 0.11±0.01 in adult horses and 0.17±0.01 in young horses. The results also showed high genetic correlations (≥0.84±0.04) between results early and later on in life. With model A, the prediction of the adult SJ ability was higher (Pearson correlation between predicted and real data: 0.33±0.01) than with model B (0.31±0.01). The implementation of alternative strategies, such as two-stage selection, could increase the expected genetic gain significantly (over 50%) compared to other strategies. This strategy could promote genetic progress, without any loss of accuracy and little additional cost.

Wheat (Triticum aestivum L.) breeding strategies can benefit from periodic evaluation of genetic gains for physiological and morphological traits, and their contribution to yield progress over time in a particular environment. The objective of this research was to expand the recent work at Virginia Tech on genetic yield improvement in soft red winter (SRW) wheat and determine the magnitude of progress for several physiological traits in 50 SRW wheat cultivars released from 1919 to 2009. Physiological traits evaluated here were extensively reported in the literature to be relevant for future wheat breeding as they directly contributed to yield increase under optimum and suboptimal environmental conditions; these traits include canopy temperature depression (CTD), flag leaf width (W), flag leaf area (LA), flag leaf dry weight (DW), flag leaf specific area (SLA), SPAD (soil plant analysis development) chlorophyll reading, and grain 13C isotope discrimination (Δ). Replicated experiments were performed at Warsaw and Holland, VA, in 2009–2010 and 2010–2011 growing seasons. Results showed that three traits consistently changed in magnitude over time and, at the same time, were significantly (p

Streptococcus iniae and S. agalactiae are both economically important Gram positive bacterial pathogens affecting the globally farmed tilapia (Oreochromis spp.). Historically, control of these bacteria in tilapia culture has included biosecurity, therapeutants and vaccination strategies. Genetic gains in performance traits have been realized for Nile tilapia (Oreochromis niloticus) and interest in breeding for disease resistance has recently received attention. The goal of this study was three fold: 1) to verify previous results demonstrating heritability of S. iniae resistance in Nile tilapia families using increased numbers of fish per family; 2) to determine if realized genetic gain in resistance and/or susceptibility to S. iniae can be obtained following positive assortative mating between parents with high or low estimated breeding values (EBV); and 3) to determine if resistance to S. iniae and S. agalactiae capsular type Ib is genetically correlated. A total of 144 and 130 full sib families were challenged intraperitoneally with S. iniae and intramuscularly with S. agalactiae Ib, respectively. Cumulative mortality at test end was 46% for S. iniae and 68% for S. agalactiae. There was a high additive genetic component found for survival in fish injected with S. iniae (estimated heritability 0.52 ± 0.12) and with S. agalactiae (estimated heritability 0.38 ± 0.11). The S. iniae challenge results confirmed additive genetic variation in resistance of Nile tilapia to S. iniae. We also demonstrated via assortative mating that genetic gain for survival to S. iniae is possible. The genetic correlation between resistance to S. iniae and S. agalactiae Ib was not significantly different from zero (rg = − 0.30 ± 0.19). The lack of correlation suggests if resistance to both Streptococcus sp. is desired, selection for both traits must be simultaneous. Selection of fish to improve survival to Streptococcus sp. may require a thorough understanding of the type of pathogen prevalent in the region so that custom genetic material may be tailored to meet the needs of the individual farm and/or region.

Several perennial grasses have been studied as energetic feedstock due to high lignocellulosic production, making it an alternative bioenergy source. This is the first study to investigate the aptitude of elephant grass ( Pennisetum purpureum Schum.), aiming to breed it for bioenergy production via direct combustion of biomass. The evaluation of the aptitude and the estimates of the genotypic values were carried out using the mixed models methodology. The canonical correlation analyses were carried out among morpho-agronomic and biomass quality traits for the groups Napier and Cameroon. Complementarily, it was used path analysis with calorific value as the principle variable. Elephant grass presented 22.59 Mg ha −1 mean biomass production. Cameroon group presents the greatest aptitude to be used as bioenergetic raw material via direct combustion of biomass, with 24.13 Mg ha −1 total dry biomass, and 18.16 MJ kg −1 calorific value. The ash content has high correlation and high direct effect on the calorific value. Genetic breeding for morpho-agronomic traits within the Cameroon group is recommended. The canonical correlation analyses and path analyses indicate that in the initial stages of elephant grass breeding program, there is a possibility of indirect selection via morpho-agronomic traits to obtain genetic gain in calorific value. In this sense, tandem selection within the Cameroon group could be a good option, in which the genotypes with the tallest and the thickest stalk diameter should be selected among the genotypes with the greatest dry matter content.