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Pinus pinaster is a very important species for the Galician wood industry. A genetic breeding program was started in the 1980s to select plus trees based on growth and straightness. In this study, we estimated genetic parameters, juvenile-mature correlations and genetic gains in basic density (BD) and the dynamic modulus of elasticity (MOEd) in Galician breeding families, as well as their relation to volume, straightness, and tree slenderness. All traits were measured at a tree age of 12 years in three half-sib progeny trials. Wood quality traits were also measured at 24 years in two other trials. All progeny trials followed a randomized complete block design and the data were analyzed using several mixed-model approaches. The individual heritability of MOEd remained stable at both ages (~ 0.39) but decreased with age for BD (from 0.44 at age 12 to 0.24 at age 24). The high juvenile-mature correlations (0.51 for BD, 0.57 for MOEd) observed support the viability of early selection for both traits at 12 years. Both wood quality traits correlated positively with each other and weakly with volume, straightness and tree slenderness. Selecting a minimum number of the best families, based on volume or any wood quality trait, would generate genetic gains for the selecting trait and prevent genetic losses of non-selecting traits. We also identified specific families showing positive genetic gains for all traits. The research indicates that either or both of these wood quality traits could be included as new selection criteria in the Galician breeding program. [ABSTRACT FROM AUTHOR]

Eucalyptus urophylla S.T. Blake, an important economic tree species, is widely cultivated as a raw material source for pulpwood, veneer plywood, and sawlog timber in southern China. As a tree in multiple environments, tree-breeding programs can assess genotype by environment (G × E) interactions and identify the suitable genotype for a specific environment. G × E interactions related to growth traits and soil factors have not been adequately studied for clones of Eucalyptus urophylla and its hybrids. To examine this important question, trials containing 20 clones of E. urophylla and its hybrids were established at three sites in southern China: Shankou (SK), Tiantang (TT), and Xiniujiao (XNJ). These sites each have different soil conditions but similar geographical and climatic conditions. With the data across nearly eight years, average phenotypic trends and broad sense repeatability (H2) were modeled, G×E interactions between clones and diverse soil environments were estimated, genetic gains of clones were calculated, and the adaptabilities of E. urophylla clones in different soil environments were compared. Average survival trends for clones tended to show a moderate decrease while growth traits tended to show sharp increases with age. At the same age, sites were ordered for average survival and growth traits as TT>SK>XNJ while H2 values for growth traits by site followed the basic order TT>SK>XNJ. The H2 values for growth traits at SK tended to increase at first, platform, and then smooth with age. The H2 values for growth traits at TT were high and stable across ages, and those at XNJ tended to undulate largely at a relatively low level across ages. Genetic correlations for growth traits between any pair of sites tended to increase at first and then decrease. A genetic correlation was strong between SK and TT, intermediate between SK and XNJ, and weak between TT and XNJ. It was concluded that: (1) clones tended to be adapted better to an environment with acidic and loamy soil with a clay content of about 45.6%, the soil depth from the surface to parent material about 1.5 m, and the previous vegetation of Eucalypts. (2) The G×E interactions between clones and sites are weaker if the environmental conditions between the sites are similar, and which are stronger if the environmental conditions between the sites are different. (3) The optimum selection age for clones ranged from 1.5 to 3.5 years old, while the optimum selection growth trait is individual tree volume. [ABSTRACT FROM AUTHOR]

Eucalyptus urophylla S.T. Blake, an important economic tree species, is widely cultivated as a raw material source for pulpwood, veneer plywood, and sawlog timber in southern China. As a tree in multiple environments, tree-breeding programs can assess genotype by environment (G × E) interactions and identify the suitable genotype for a specific environment. G × E interactions related to growth traits and soil factors have not been adequately studied for clones of Eucalyptus urophylla and its hybrids. To examine this important question, trials containing 20 clones of E. urophylla and its hybrids were established at three sites in southern China: Shankou (SK), Tiantang (TT), and Xiniujiao (XNJ). These sites each have different soil conditions but similar geographical and climatic conditions. With the data across nearly eight years, average phenotypic trends and broad sense repeatability (H2) were modeled, G×E interactions between clones and diverse soil environments were estimated, genetic gains of clones were calculated, and the adaptabilities of E. urophylla clones in different soil environments were compared. Average survival trends for clones tended to show a moderate decrease while growth traits tended to show sharp increases with age. At the same age, sites were ordered for average survival and growth traits as TT>SK>XNJ while H2 values for growth traits by site followed the basic order TT>SK>XNJ. The H2 values for growth traits at SK tended to increase at first, platform, and then smooth with age. The H2 values for growth traits at TT were high and stable across ages, and those at XNJ tended to undulate largely at a relatively low level across ages. Genetic correlations for growth traits between any pair of sites tended to increase at first and then decrease. A genetic correlation was strong between SK and TT, intermediate between SK and XNJ, and weak between TT and XNJ. It was concluded that: (1) clones tended to be adapted better to an environment with acidic and loamy soil with a clay content of about 45.6%, the soil depth from the surface to parent material about 1.5 m, and the previous vegetation of Eucalypts. (2) The G×E interactions between clones and sites are weaker if the environmental conditions between the sites are similar, and which are stronger if the environmental conditions between the sites are different. (3) The optimum selection age for clones ranged from 1.5 to 3.5 years old, while the optimum selection growth trait is individual tree volume.

Hancornia speciosa is a fruit tree species with the potential for exploitation, which makes the adoption of strategies related to its conservation and breeding relevant. Our study aimed to investigate the reproductive phenology, estimate genetic variability, and identify superior H. speciosa genotypes among the accessions that compose the germplasm collection of the Federal University of Goiás, Brazil. Experimental data were obtained from 143 individual accessions. Evaluation of reproductive phenology was conducted on an arbitrary scale of points assigned to trees monthly. Morphological characterization was based on a list of 20 qualitative descriptors and 12 quantitative traits. The dissimilarity between and within botanical varieties and their correlation with the geographic distance of the original populations were investigated. Analysis of variance components was performed using the Restricted Maximum Likelihood/Best Linear Unbiased Prediction procedure using two linear models. The selection of the ≈ 10% best individual accessions was performed considering genetic and genotypic values. Except for of H. speciosa var. speciosa, the botanical varieties that compose the germplasm collection showed similar reproductive patterns, with a peak in fruit appearance in August. Morphological dissimilarity was smaller within botanical varieties. Among the botanical varieties, dissimilarity was generally positively correlated with geographic distance. The adoption of a multivariate selection index procedure enables the prediction of genetic gains, resulting in the selection of genotypes from different similarity groups. Clone selection is the most promising strategy for the breeding of H. speciosa, thus ensuring a better response to selection in the short term than recurrent selection. [ABSTRACT FROM AUTHOR]

The growth of Nelore cattle was analysed considering the following performance parameters; the effect of the calving order of cows on the phenotypic expression of birth weight (BW), average daily gain from birth to weaning (BWG), and weaning weight (WW), the estimated genetic parameters for the traits, including the covariance components between direct and maternal genetic effects. Genetic trends and correlated responses were also obtained for the studied traits. The calving order of cows, as well as other fixed effects used to obtain the adjusted phenotypic means, were statistically significant (p < 0.001) for studied traits. Direct heritability was estimated at 0.24 ± 0.01 (BW), 0.15 ± 0.01 (BWG), and 0.18 ± 0.01 (WW), while maternal heritability was 0.06 ± 0.01 (BW), 0.12 ± 0.01 (BWG), and 0.11 ± 0.01 (WW). The correlations between direct and maternal effects within the same trait were negligible. Moderate to higher direct genetic correlations (ranging from 0.54 ± 0.04 to 0.98 ± 0.01) and maternal genetic correlations (ranging from 0.34 ± 0.09 to 0.99 ± 0.002) were estimated between the studied traits. Unlike direct genetic effects, there was no significant change in maternal genetic effects over time (p > 0.05). These results indicated the need for revising selection indexes for enhancing maternal ability. Correlated responses were generally lower compared to direct responses, except for BWG. The selection for BWG, considering the maternal genetic effect, would be more efficient to improve maternal ability of the cows for pre-weaning growth in relation to selection for WW. Our results found that direct genetic merit improves pre-weaning weight and this trait can be incorporated into the breeding goal as reflected in the WW. [ABSTRACT FROM AUTHOR]

Monitoring genetic gain is required in crop improvement programs in order to assess the effectiveness of breeding initiatives. The periodic measurement of genetic gain will quantify the efficiency of new technologies incorporated into the program. Here, a total of 24 cultivars (20 released from Zimbabwe's National Breeding program (ZNBP) plus 4 released by the largest and oldest private seed company in Zimbabwe, Seed Co) over the period of 1900–2016, were evaluated across 10 locations in Zimbabwe. The testing locations represented agro-ecologies where maize is optimally grown and where maize production is under threat from climate change-induced abiotic stresses, particularly drought and heat stress, in Zimbabwe. The 24 cultivars were laid out across all the locations using the alpha (0.1) lattice design replicated two times with six incomplete blocks nested in each of the replicates. The genetic gains were estimated at 61 kg ha−1 yr−1, 25 kg ha−1 yr−1, 6 kg ha−1 yr−1, and 2 kg ha−1 yr−1 under optimal, random drought stress, heat stress, and managed drought stress conditions, respectively. The results were comparable with those from other studies where newly released cultivars yielded more than old cultivars. Overall, the results demonstrated that over a century, the ZNBP has been making significant progress in yield increments in its maize genotypes. [ABSTRACT FROM AUTHOR]

Genetic gain estimation in a breeding program provides an opportunity to monitor breeding efficiency and genetic progress over a specific period. The present study was conducted to (i) assess the genetic gains in grain yield of the early maturing maize hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) Southern African breeding program during the period 2000–2018 and (ii) identify key agronomic traits contributing to the yield gains under various management conditions. Seventy-two early maturing hybrids developed by CIMMYT and three commercial checks were assessed under stress and non-stress conditions across 68 environments in seven eastern and southern African countries through the regional on-station trials. Genetic gain was estimated as the slope of the regression of grain yield and other traits against the year of first testing of the hybrid in the regional trial. The results showed highly significant (p< 0.01) annual grain yield gains of 118, 63, 46, and 61 kg ha−1 year−1 under optimum, low N, managed drought, and random stress conditions, respectively. The gains in grain yield realized in this study under both stress and non-stress conditions were associated with improvements in certain agronomic traits and resistance to major maize diseases. The findings of this study clearly demonstrate the significant progress made in developing productive and multiple stress-tolerant maize hybrids together with other desirable agronomic attributes in CIMMYT’s hybrid breeding program. [ABSTRACT FROM AUTHOR]

Genetic gain estimation in a breeding program provides an opportunity to monitor breeding efficiency and genetic progress over a specific period. The present study was conducted to (i) assess the genetic gains in grain yield of the early maturing maize hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) Southern African breeding program during the period 2000–2018 and (ii) identify key agronomic traits contributing to the yield gains under various management conditions. Seventy-two early maturing hybrids developed by CIMMYT and three commercial checks were assessed under stress and non-stress conditions across 68 environments in seven eastern and southern African countries through the regional on-station trials. Genetic gain was estimated as the slope of the regression of grain yield and other traits against the year of first testing of the hybrid in the regional trial. The results showed highly significant (p< 0.01) annual grain yield gains of 118, 63, 46, and 61 kg ha−1 year−1 under optimum, low N, managed drought, and random stress conditions, respectively. The gains in grain yield realized in this study under both stress and non-stress conditions were associated with improvements in certain agronomic traits and resistance to major maize diseases. The findings of this study clearly demonstrate the significant progress made in developing productive and multiple stress-tolerant maize hybrids together with other desirable agronomic attributes in CIMMYT’s hybrid breeding program.

Investigating the relationship between grain yield and main agronomic traits and understanding the trend of changes in traits during breeding history are important for breeding strategies. In order to determine the trend of changes in improved wheat cultivars and calculate the genetic gain of yield and related traits, 20 spring wheat cultivars released for the northern climate of the Iran during the years 1968 to 2018 were evaluated. Cultivars were cultivated in a randomized complete block design with three replications in Gorgan, Gonbad, Sari and Moghan in three consecutive years (2015–18). Morphological and phenological traits and grain yield and related traits were assessed in each year. Linear regression analysis between investigated characteristics and year of cultivar release showed that the grain yield, biological yield, harvest index, number of spikes per square meter, thousand-kernel weight and grain filling rate were significantly increased. No significant changes, however, were observed during breeding programs in maturity-related traits such as days to heading, days to anthesis, days to maturity, duration of grain filling, plant height, peduncle length, spike length and number of grains per spike. According to the positive and significant correlation between biomass, harvest index, number of spikes per square meter and thousand-kernel weight with grain yield, it seems that breeders in the northern climate of the country have been selected these traits to increase grain yield during the process of breeding cultivars. [ABSTRACT FROM AUTHOR]

Maize is a commodity crop providing millions of people with food, feed, industrial raw material and economic opportunities. However, maize yields in Africa are relatively stagnant and low, at a mean of 1.7 t ha−1 compared with the global average of 6 t ha−1. The yield gap can be narrowed with accelerated and precision breeding strategies that are required to develop and deploy high‐yielding and climate‐resilient maize varieties. Genomic and phenotypic selections are complementary methods that offer opportunities for the speedy choice of contrasting parents and derived progenies for hybrid breeding and commercialization. Genomic selection (GS) will shorten the crop breeding cycle by identifying and tracking desirable genotypes and aid the timeous commercialization of market‐preferred varieties. The technology, however, has not yet been fully embraced by most public and private breeding programmes, notably in Africa. This review aims to present the importance, current status, challenges and opportunities of GS to accelerate genetic gains for economic traits to speed up the breeding of high‐yielding maize varieties. The first section summarizes genomic selection and the contemporary phenotypic selection and phenotyping platforms as a foundation for GS and trait integration in maize. This is followed by highlights on the reported genetic gains and progress through phenotypic selection and GS for grain yield and yield components. Training population development, genetic design and statistical models used in GS in maize breeding are discussed. Lastly, the review summarizes the challenges of GS, including prediction accuracy, and integrates GS with speed breeding, doubled haploid breeding and genome editing technologies to increase breeding efficiency and accelerate cultivar release. The paper will guide breeders in selection and trait introgression using GS to develop cultivars preferred by the marketplace. [ABSTRACT FROM AUTHOR]

Svalöf is a yellow-skinned, light yellow-fleshed, high-yielding table potato cultivar for the high latitude of Scandinavia, showing partial resistance to Phytophthora infestans (causing late blight) and same specific gravity as the mealy cultivar King Edward, which is preferred in the fresh market by consumers in Sweden. It was selected as breeding clone SLU 1314015 in the first clonal generation (T1) at the late-blight prone site of Mosslunda (Skåne, southern Sweden) in October 2015. The cross for obtaining it was made by the Swedish University of Agricultural Sciences in 2013 involving the breeding clone D09 1:2 1701 as female parent and the Dutch cultivar Carolus as male parent. Svalöf show very large, round-oval tubers with shallow eyes and smooth skin. Its tuber yield averaged above 6%, 23%, 25% and 59% of Dutch cultivars Connect, Fontane, Carolus and Bintje, respectively, across multi-site trials in Sweden. Its unstable reducing sugar in the tuber flesh, as determined by multi-site testing, suggests that it will not be suitable for the crisp or chip processing. SLU's Svensk potatisförädling is seeking registration to be included in the Svenska Sortlistan, which lists cultivars available and is a pre-condition for certification of planting materials in the European Union. The release of Svalöf as new potato cultivar will be the first entirely bred for this crop in Sweden since the mid-1990s. [ABSTRACT FROM AUTHOR]

Castanopsis hystrix, a timber resource from Southeast Asia, is characterized by rapid growth and high yield, but plantation quality and efficiency improvements are required. Twenty-year-old C. hystrix experimental forests in Yulin, Liuzhou, and Pingxiang in Guangxi Province, China, comprising 21 open-pollinated half-sib families, were used in this study. Genetic variations in the growth (tree height, diameter at breast height (DBH), and volume (V)) and morphological (height to live crown base (HCB), crown width (CW), and branch angle) traits were assessed, and the genetic parameters were estimated to clarify the genotype × environment interaction effects. The average values for the tree height, DBH, V, HCB, CW, and branch angle were 16.33 m, 17.25 cm, 0.21 m3, 6.68 m, 2.15 m, and 45.45°, respectively. The most important sources of variance for the tree height, DBH, V, and HCB were the block and family, whereas the location, family, and family × location had significant impacts on the tree height, DBH, V, and HCB (p < 0.01). The family heritability for each trait was 0.35, 0.38, 0.62, and 0.19, respectively. Excellent families with strong adaptability and genetic stability were identified using BLUP–GGE biplots for single and multiple traits. The results provide a theoretical basis for the efficient cultivation of C. hystrix in South China. [ABSTRACT FROM AUTHOR]

Inbreeding depression (ID) is caused by increased homozygosity in the offspring after selfing. Although the self-compatible, highly heterozygous, tetrasomic polyploid potato (Solanum tuberosum L.) suffers from ID, some argue that the potential genetic gains from using inbred lines in a sexual propagation system of potato are too large to be ignored. The aim of this research was to assess the effects of inbreeding on potato offspring performance under a high latitude and the accuracy of the genomic prediction of breeding values (GEBVs) for further use in selection. Four inbred (S1) and two hybrid (F1) offspring and their parents (S0) were used in the experiment, with a field layout of an augmented design with the four S0 replicated in nine incomplete blocks comprising 100, four-plant plots at Umeå (63°49′30″ N 20°15′50″ E), Sweden. S0 was significantly (p < 0.01) better than both S1 and F1 offspring for tuber weight (total and according to five grading sizes), tuber shape and size uniformity, tuber eye depth and reducing sugars in the tuber flesh, while F1 was significantly (p < 0.01) better than S1 for all tuber weight and uniformity traits. Some F1 hybrid offspring (15–19%) had better total tuber yield than the best-performing parent. The GEBV accuracy ranged from −0.3928 to 0.4436. Overall, tuber shape uniformity had the highest GEBV accuracy, while tuber weight traits exhibited the lowest accuracy. The F1 full sib's GEBV accuracy was higher, on average, than that of S1. Genomic prediction may facilitate eliminating undesired inbred or hybrid offspring for further use in the genetic betterment of potato. [ABSTRACT FROM AUTHOR]

Estimating genetic gains is vital to optimize breeding programs for increased efficiency. Genetic gains should translate into productivity gains if returns to investments in breeding and impact are to be realized. The objective of this study was to estimate genetic gain for grain yield and key agronomic traits in precommercial and commercial maize varieties from public and private breeding programs tested in (i) national performance trials (NPT), (ii) era trial and, (iii) compare the trends with the national average. The study used (i) historical NPT data on 419 improved maize varieties evaluated in 23 trials at 6-8 locations each between 2008 and 2020, and (ii) data from an era trial of 54 maize hybrids released between 1999 and 2020. The NPT data was first analyzed using a mixed model and resulting estimate for each entry was regressed onto its first year of testing. Analysis was done over all entries, only entries from National Agricultural Research Organization (NARO), International Maize and Wheat Improvement Center (CIMMYT), or private seed companies. Estimated genetic gain was 2.25% or 81 kg ha-1 year-1 from the NPT analysis. A comparison of genetic trends by source indicated that CIMMYT entries had a gain of 1.98% year-1 or 106 kg ha-1 year-1. In contrast, NARO and private sector maize entries recorded genetic gains of 1.30% year-1 (59 kg ha-1 year-1) and 1.71% year-1 (79 kg ha-1 year-1), respectively. Varieties from NARO and private sector showed comparable mean yields of 4.56 t ha-1 and 4.62 t ha-1, respectively, while hybrids from CIMMYT had a mean of 5.37 t ha-1. Era analysis indicated significant genetic gain of 1.69% year-1 or 55 kg ha-1 year-1, while a significant national productivity gain of 1.48% year-1 (37 kg ha-1 year-1) was obtained. The study, thus, demonstrated the importance of public-private partnerships in development and delivery of new genetics to farmers in Uganda. [ABSTRACT FROM AUTHOR]

In view of the need to develop new popcorn cultivars and considering the uncertainties in choosing the most appropriate breeding methods to ensure consistent genetic progress, simultaneously for both popping expansion and grain yield, this study addressed the efficiency of interpopulation recurrent selection regarding genetic gains, the study of the response in genetic parameters as well as heterotic effects on the control of the main agronomic traits of popcorn. Two populations were established, Pop1 and Pop2. A total of 324 treatments were evaluated, which consisted of 200 half-sib families (100 from Pop1 and 100 from Pop2), 100 full-sib families from the two populations and 24 controls. The field experiment was arranged in a lattice design with three replications in two environments, in the north and northwest regions of the State of Rio de Janeiro, Brazil. The genotype × environment interaction was partitioned and the genetic parameters, heterosis and predicted gains were estimated by the Mulamba and Mock index, based on selection results in both environments. The genetic parameters detected variability that can be explored in successive interpopulation recurrent selection cycles. Exploring heterosis for GY, PE and yield components is a promising option to increase grain yield and quality. The Mulamba and Mock index was efficient in predicting the genetic gains in GY and PE. Interpopulation recurrent selection proved effective to provide genetic gains for traits with predominantly additive and dominance inheritance. [ABSTRACT FROM AUTHOR]

Estimating genetic gains is vital to optimize breeding programs for increased efficiency. Genetic gains should translate into productivity gains if returns to investments in breeding and impact are to be realized. The objective of this study was to estimate genetic gain for grain yield and key agronomic traits in pre-commercial and commercial maize varieties from public and private breeding programs tested in (i) national performance trials (NPT), (ii) era trial and, (iii) compare the trends with the national average. The study used (i) historical NPT data on 419 improved maize varieties evaluated in 23 trials at 6-8 locations each between 2008 and 2020, and (ii) data from an era trial of 54 maize hybrids released between 1999 and 2020. The NPT data was first analyzed using a mixed model and resulting estimate for each entry was regressed onto its first year of testing. Analysis was done over all entries, only entries from National Agricultural Research Organization (NARO), International Maize and Wheat Improvement Center (CIMMYT), or private seed companies. Estimated genetic gain was 2.25% or 81 kg ha-1 year-1 from the NPT analysis. A comparison of genetic trends by source indicated that CIMMYT entries had a gain of 1.98% year-1 or 106 kg ha-1 year-1. In contrast, NARO and private sector maize entries recorded genetic gains of 1.30% year-1 (59 kg ha-1 year-1) and 1.71% year-1 (79 kg ha-1 year-1), respectively. Varieties from NARO and private sector showed comparable mean yields of 4.56 t ha-1 and 4.62 t ha-1, respectively, while hybrids from CIMMYT had a mean of 5.37 t ha-1. Era analysis indicated significant genetic gain of 1.69% year-1 or 55 kg ha-1 year-1, while a significant national productivity gain of 1.48% year-1 (37 kg ha-1 year-1) was obtained. The study, thus, demonstrated the importance of public-private partnerships in development and delivery of new genetics to farmers in Uganda.

Maintaining low levels of rust incidence (caused by Puccinia novopanici) in switchgrass (Panicum virgatum L.) breeding populations is a priority for the USDA-ARS program engaged in improving cultivars for high biomass yield and quality. Essential to this goal is the unbiased and accurate estimation of genetic parameters to predict the merits of parents and progeny. Spores of the fungus were inoculated in greenhouse-grown seedling progeny of 31 half-sib families in generation 2 (Gen 2) of a composite Summer × Kanlow population for evaluation of rust incidence on the leaves with a 0–9 rating scale. Two parents were later chosen to cross and develop a linkage mapping population as Gen 3. The Gen 2, 3, and Kanlow seedlings were transplanted into the field located near Mead, NE, in early June 2020 and laid out as a replicated row–column design with six blocks of single-row plots of five plants each. The field trial was rated in September 2021 and 2022 with a 0–4 scale. Lab and field data were subjected to univariate linear mixed models via the restricted maximum likelihood to extract the variance components needed to predict the breeding values. The additive genetic variation was substantial (p < 0.01), enough to result in high heritability estimates ranging from 0.42 ± 14 to 0.73 ± 0.09 at the individual and family mean levels. This result implies that rust resistance is under strong genetic control to use mass selection for obtaining satisfactory gains. A possible rust incidence x year interaction was detected with a Spearman correlation of breeding values of −0.38, caused by significant rank changes of the Gen 3 genotypes in 2022 (a high heat and drought year). Genetic gains were predicted to reduce rust incidence scores by at least two points on the rating scale when selecting backwards, and by one point when selecting individual candidates as parents of the next generation. Faster gains (31 and 59%) were realized relative to the second generation by respectively selecting the top 10% of the families in Gen 3 or the top 10% of genotypes within this group. Based on these results, strategies for controlling the incidence of rust will be developed to optimize gains in the other traits of economic importance. [ABSTRACT FROM AUTHOR]

Technologies and innovations are critical for addressing the future food system needs where genetic resources are an essential component of the change process. Advanced breeding tools like "genome editing" are vital for modernizing crop breeding to provide game-changing solutions to some of the "must needed" traits in agriculture. CRISPR/Cas-based tools have been rapidly repurposed for editing applications based on their improved efficiency, specificity and reduced off-target effects. Additionally, precise gene-editing tools such as base editing, prime editing, and multiplexing provide precision in stacking of multiple traits in an elite variety, and facilitating specific and targeted crop improvement. This has helped in advancing research and delivery of products in a short time span, thereby enhancing the rate of genetic gains. A special focus has been on food security in the drylands through crops including millets, teff, fonio, quinoa, Bambara groundnut, pigeonpea and cassava. While these crops contribute significantly to the agricultural economy and resilience of the dryland, improvement of several traits including increased stress tolerance, nutritional value, and yields are urgently required. Although CRISPR has potential to deliver disruptive innovations, prioritization of traits should consider breeding product profiles and market segments for designing and accelerating delivery of locally adapted and preferred crop varieties for the drylands. In this context, the scope of regulatory environment has been stated, implying the dire impacts of unreasonable scrutiny of genome-edited plants on the evolution and progress of much-needed technological advances. [ABSTRACT FROM AUTHOR]

Pedigree-based best linear unbiased prediction (pBLUP) is an effective method for genetic evaluation. The objective of this study was to assess the efficacy of pBLUP to develop superior inbred lines, using field and simulated data. This study was based on the data of 30,986 plants from six S0 generations and eight inbred progeny trials (S1–S4), performed over eight years. We measured the grain yield and the expansion volume (EV). We also simulated the EV and grain yield of 5000 plants (S0–S4) in two in silico populations, assuming 300 and 400 genes distributed across 10 chromosomes of 200 cM, respectively, and 10% of pleiotropic genes. We selected selfed plants based on the predicted additive value for EV by fitting the individual model in inbred population. The use of pBLUP provided total genetic gains in EV in the range of 1 to 45%, inversely proportional to the level of improvement of the population, and indirect changes in grain yield in the range of −17 to 3%. Only from the analysis of the in silico populations, assuming selection based on the true additive value and genetic gain computed from the genotypic values, there was evidence that pBLUP is superior to phenotypic mass selection. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is an important staple, as well as cash crop, in sub-Saharan Africa (SSA). However, its production is severely constrained by low soil nitrogen (low N). Fifty-four early-maturing hybrids developed during three breeding periods, (2008–2010, 2011–2013 and 2014–2016) were evaluated under low (30 kg ha−1) and high (120 kg ha−1) soil nitrogen (N) in Ile-Ife and Mokwa, Nigeria, from 2017 to 2019. The study was designed to (i) determine the genetic gains in grain yield of the early-maturing maize hybrids developed during the three breeding periods, (ii) determine the relationship between grain yield and other agronomic traits and (iii) identify the highest-yielding and most stable hybrids under low- and high-N environments. The 54 hybrids were evaluated using a 6 × 9 lattice design with three replications. Mean squares for hybrids were significant for measured traits under low- and high-N environments, except the mean squares for stalk lodging and EPP under low N. Annual genetic gains in grain yield were 75 kg ha−1 year−1 (2.91%) and 55 kg ha−1 year−1 (1.33%) under low- and high-N environments, respectively, indicating that substantial gains were achieved in the genetic enhancement of the early-maturing hybrids. The hybrids TZdEI 314 × TZdEI 105, TZdEI 378 × TZdEI 173, ENT 12 × TZEI 48 and TZdEI 352 × TZdEI 315 were identified as the highest-yielding and most stable across test environments and should be tested extensively on farms and commercialized in SSA. [ABSTRACT FROM AUTHOR]

Sugarcane is an important crop to the Australian economy, and the plant breeding program has contributed significantly to the success of the sugarcane industry. Currently, the Australian sugarcane breeding program is conducted at 6 research stations by Sugar Research Australia in collaboration with Wilmar Sugar. Crossing is mainly conducted in Meringa, whereas selection is carried out at 6 different stations. The selection process consists of three stages: progeny assessment trials (PATs), clonal assessment trials (CATs) and final assessment trials (FATs). It takes approximately 12 years from planting seedlings in PATs to release of a commercial variety. Key infrastructure for the efficient and effective operation of the program and activities for improving the program are presented. [ABSTRACT FROM AUTHOR]

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In view of the need to develop new popcorn cultivars and considering the uncertainties in choosing the most appropriate breeding methods to ensure consistent genetic progress, simultaneously for both popping expansion and grain yield, this study addressed the efficiency of interpopulation recurrent selection regarding genetic gains, the study of the response in genetic parameters as well as heterotic effects on the control of the main agronomic traits of popcorn. Two populations were established, Pop1 and Pop2. A total of 324 treatments were evaluated, which consisted of 200 half-sib families (100 from Pop1 and 100 from Pop2), 100 full-sib families from the two populations and 24 controls. The field experiment was arranged in a lattice design with three replications in two environments, in the north and northwest regions of the State of Rio de Janeiro, Brazil. The genotype × environment interaction was partitioned and the genetic parameters, heterosis and predicted gains were estimated by the Mulamba and Mock index, based on selection results in both environments. The genetic parameters detected variability that can be explored in successive interpopulation recurrent selection cycles. Exploring heterosis for GY, PE and yield components is a promising option to increase grain yield and quality. The Mulamba and Mock index was efficient in predicting the genetic gains in GY and PE. Interpopulation recurrent selection proved effective to provide genetic gains for traits with predominantly additive and dominance inheritance.

Fruit tree crops are an essential part of the food production systems and are key to achieve food and nutrition security. Genetic improvement of fruit trees by conventional breeding has been slow due to the long juvenile phase. Advancements in genomics and molecular biology have paved the way for devising novel genetic improvement tools like genome editing, which can accelerate the breeding of these perennial crops to a great extent. In this article, advancements in genomics of fruit trees covering genome sequencing, transcriptome sequencing, genome editing technologies (GET), CRISPR-Cas system based genome editing, potential applications of CRISPR-Cas9 in fruit tree crops improvement, the factors influencing the CRISPR-Cas editing efficiency and the challenges for CRISPR-Cas9 applications in fruit tree crops improvement are reviewed. Besides, base editing, a recently emerging more precise editing system, and the future perspectives of genome editing in the improvement of fruit and nut crops are covered. • Genetic improvement of fruit tree crops by conventional breeding has been slow due to the long juvenile phase. • Novel genetic improvement tools like genome editing can accelerate the breeding of perennial crops to a great extent. • Base editing: an emerging editing system which provides more precision in creating changes at specific loci. [ABSTRACT FROM AUTHOR]

Development of ideal breeding and crop management strategies that can improve maize grain yield under tropical environments is crucial. In the temperate regions, such yield improvements were achieved through use of genotypes that are adapted to high plant population density stress. However, tropical germplasm has poor tolerance to high plant population density stress, and thus it should be improved by introgressing temperate maize germplasm. The aim of this study was to estimate the genetic gains and identify traits associated with such gains in stable and high yielding temperate × tropical hybrids under low and high plant population densities. A total of 200 hybrids derived from a line × tester mating design of tropical × temperate germplasm were developed. These hybrids were evaluated for grain yield and allied traits under varied plant population densities. High yielding and stable hybrids, such as 15XH214, 15XH215 and 15XH121, were resistant to lodging and had higher number of leaves above the cob. The high genetic gains of 26% and desirable stress tolerance indices of these hybrids made them better performers over check hybrids under high plant population density. At high plant population density yield was correlated to stem lodging and number of leaves above the cob. Future gains in grain yield of these hybrids derived from temperate × tropical maize germplasm can be achieved by exploiting indirect selection for resistance to stem lodging and increased number of leaves above the cob under high plant density conditions. [ABSTRACT FROM AUTHOR]

For continuous genetic gains over time, a balance between genetic gain and maintaining the genetic base must be a constant concern of forest breeders. This study aims at determining the best thinning strategies for a population of Eucalyptus dunnii, by incorporating the effects of environmental heterogeneity and competition in the analysis, as well as the best growth trait regarding precision and accuracy. The population studied consisted of 160 open-pollinated families. The survival and growth (height, HT; diameter at breast height, DBH; and volume, VOL) were evaluated 4 years after planting. The growth rate data were analyzed and compared by four mixed models. Selection and thinning strategies were simulated by varying the number of families, individuals within families, and selected individuals, considering the estimated genetic gains and the effective size. The species showed good survival (89.7%) and productive performance (mean annual increment = 42 m3 ha−1 y−1). The Spatial+Competition Model provided the best fit for DBH and VOL. The strategies that allow a balance between improvement (genetic gains) and genetic conservation (effective size) consist of keeping 36 to 50% of the individuals in the test (370 to 510 trees ha−1), by reducing more intensively the number of individuals from the worst-performing families. The selection of 100 individuals with a restriction of at most one individual per family generates the largest number of effective size (Ne), with more than double the Ne obtained without restricting the individuals per family, with a small drop in genetic gain. [ABSTRACT FROM AUTHOR]

Domestication syndrome, selection pressure, and modern plant breeding programs have reduced the genetic diversity of the wheat germplasm. For the genetic gains of breeding programs to be sustainable, plant breeders require a diverse gene pool to select genes for resistance to biotic stress factors, tolerance to abiotic stress factors, and improved quality and yield components. Thus, old landraces, subspecies and wild ancestors are rich sources of genetic diversity that have not yet been fully exploited, and it is possible to utilize this diversity. Compared with durum wheat, tetraploid wheat subspecies have retained much greater genetic diversity despite genetic drift and various environmental influences, and the identification and utilization of this diversity can make a greater contribution to the genetic enrichment of wheat. In addition, using the pre-breeding method, the valuable left-behind alleles in the wheat gene pool can be re-introduced through hybridization and introgressive gene flow to create a sustainable opportunity for the genetic gain of wheat. This review provides some insights about the potential of tetraploid wheats in plant breeding and the genetic gains made by them in plant breeding across past decades, and gathers the known functional information on genes/QTLs, metabolites, traits and their direct involvement in wheat resistance/tolerance to biotic/abiotic stresses. • Genetic erosion during domestication and modern breeding programs has led to reduce the genetic diversity of wheat. • Genetic structure of wheat can be improved through genetic enrichment by diversifying allelic combinations. • Tetraploid wheat subspecies are an excellent gene pool for improving tolerance to biotic and abiotic stresses. • Utilizing genes from tetraploid wheat subspecies provide great potential for increasing grain yield and quality of durum wheat. • Synthetic hexaploid wheat is an effective genetic resource to transfer important genes from wild relatives to common wheat. [ABSTRACT FROM AUTHOR]

Evaluating genetic selection parameters of a cross between a local blackgrained rice cultivar from Magelang and an improved rice cultivar ‘Situbagendit’ is necessary to check the efffectiveness of selection in advanced generations, i.e. F4, F5 and F6 generation. The objective of this study was to compare and evaluate changing in several genetic parameters of the generations so that we can assess the selection effectiveness. Randomly picked 48 lines of F4, F5 and F6 generation, respectively, along with their parents, were evaluated on a farmer’s field in Pakem, Yogyakarta from May until September 2016. The experiment was arranged in an incomplete randomized design with two replications. Seed of each F4, F5 and F6 lines with their parents were planted in 1 m × 2 m plot, with 20 cm × 20 cm plant spacing. For each plot 40 individuals were planted. The agronomic characters were evaluated: plant height, productive tillers, pericarp color, full grains, empty grains, weight of 1000 seeds, days to flowering and days to maturing. Genetic variances, heritability and expected genetic gain among and within family from the advanced generations were evaluated and compared. Results showed that heritability and genetic gains value whether from selected or unselected generation need more emphasis on within family selection especially in generative (full grains, empty grains and weight of 1000 seed) characters.

Maize (Zea mays L.) is an important staple, as well as cash crop, in sub-Saharan Africa (SSA). However, its production is severely constrained by low soil nitrogen (low N). Fifty-four early-maturing hybrids developed during three breeding periods, (2008–2010, 2011–2013 and 2014–2016) were evaluated under low (30 kg ha−1) and high (120 kg ha−1) soil nitrogen (N) in Ile-Ife and Mokwa, Nigeria, from 2017 to 2019. The study was designed to (i) determine the genetic gains in grain yield of the early-maturing maize hybrids developed during the three breeding periods, (ii) determine the relationship between grain yield and other agronomic traits and (iii) identify the highest-yielding and most stable hybrids under low- and high-N environments. The 54 hybrids were evaluated using a 6 × 9 lattice design with three replications. Mean squares for hybrids were significant for measured traits under low- and high-N environments, except the mean squares for stalk lodging and EPP under low N. Annual genetic gains in grain yield were 75 kg ha−1 year−1 (2.91%) and 55 kg ha−1 year−1 (1.33%) under low- and high-N environments, respectively, indicating that substantial gains were achieved in the genetic enhancement of the early-maturing hybrids. The hybrids TZdEI 314 × TZdEI 105, TZdEI 378 × TZdEI 173, ENT 12 × TZEI 48 and TZdEI 352 × TZdEI 315 were identified as the highest-yielding and most stable across test environments and should be tested extensively on farms and commercialized in SSA.

Aluminium toxicity in acidic soils (Al) and the maize streak virus disease (MSV) cause significant losses in maize productivity. These constraints can occur simultaneously in sub-Saharan Africa but there are no maize hybrids that combine resistance for both stresses. Therefore, the objectives of the study were to determine combining ability, gene action and heterosis for MSV and Al tolerance in maize. Ninety-nine experimental hybrids were generated from a 10 × 10 factorial mating design. The experimental maize hybrids, and 21 commercial hybrids were evaluated for MSV resistance under artificial infestation in Zimbabwe, and for grain yield and agronomic performance across eight environments in South Africa and Zimbabwe. Ninety-seven experimental hybrids and five standard control hybrids were evaluated for Al tolerance in a laboratory in South Africa. There were significant (p < 0.05) differences among hybrids for agronomic traits, grain yield, and MSV and Al toxicity tolerance. Only general combining ability effects were significant (p < 0.05) for grain yield and grain moisture content, while specific combining ability effects were significant (p < 0.05) for number of ears and ear prolificacy. Both GCA and SCA effects were significant for the Al toxicity tolerance related traits, indicating that Al tolerance was governed by both additive and non-additive gene action. Although hybrids displayed highly significant variation for MSV resistance, the GCA and SCA mean squares were not significant and only accounted for 59% of the hybrid sum of squares, suggesting that MSV resistance was partly under qualitative inheritance. The F1 hybrids displayed MSV severity scores similar to those of their MSV resistant parents, suggesting that probably simple dominance gene effects were involved. The hybrids also displayed significantly high levels of heterosis for both Al and MSV resistance, indicating that hybridisation would be effective in generating improved varieties. At least 60% of the hybrids were resistant to Al toxicity and more than 87% were MSV resistant, indicating that there is potential to develop varieties with resistance to both stresses. [ABSTRACT FROM AUTHOR]

Breeders have two non-exclusive strategic investment options for increasing smallholder farmers' and consumers' livelihoods through genetic improvement of crop varieties: (i) enhancing productivity; and (ii) enhancing value and market access. New Rice for Africa (NERICA) varieties with superior agronomic characteristics were bred and introduced in various African countries in the early 2000s. Two decades later, drought tolerant NERICA4 is among the popular upland rice varieties grown across Africa. We analyze market evidence for NERICA4 from Uganda in 2011, i.e. well before it massively reached urban markets, where it is currently commingled with standard rice. We then compare the breeding priorities that would have ensued from the 2011 market evidence with the reality a decade later. Non-hypothetical auction experiments with consumers were conducted in urban Uganda in 2011 to predict potential market share and value of non-fragrant NERICA4 and fragrant NERICA1, relative to two market standards, i.e. non-fragrant Kaiso, and Supa, the most popular fragrant rice variety in the region. Average consumer bids positioned the two NERICAs between both market standards. Whereas NERICA1 easily outcompeted NERICA4 and Kaiso in the non-fragrant rice category, it failed to compete with Supa in the fragrant category. The 2011 market evidence would have suggested breeders prioritize investment in breeding programs for fragrant NERICAs to help smallholders gain access to high-value markets and expand consumers' choice with cheaper fragrant rice alternatives. However, the popularity of NERICA4 relative to NERICA1 in farmers' fields seems to suggest that agronomic genetic gains may have outweighed market traits such as fragrance. [ABSTRACT FROM AUTHOR]

Summary: Agricultural production faces a Herculean challenge to feed the increasing global population. Food production systems need to deliver more with finite land and water resources while exerting the least negative influence on the ecosystem. The unpredictability of climate change and consequent changes in pests/pathogens dynamics aggravate the enormity of the challenge. Crop improvement has made significant contributions towards food security, and breeding climate‐smart cultivars are considered the most sustainable way to accelerate food production. However, a fundamental change is needed in the conventional breeding framework in order to respond adequately to the growing food demands. Progress in genomics has provided new concepts and tools that hold promise to make plant breeding procedures more precise and efficient. For instance, reference genome assemblies in combination with germplasm sequencing delineate breeding targets that could contribute to securing future food supply. In this review, we highlight key breakthroughs in plant genome sequencing and explain how the presence of these genome resources in combination with gene editing techniques has revolutionized the procedures of trait discovery and manipulation. Adoption of new approaches such as speed breeding, genomic selection and haplotype‐based breeding could overcome several limitations of conventional breeding. We advocate that strengthening varietal release and seed distribution systems will play a more determining role in delivering genetic gains at farmer's field. A holistic approach outlined here would be crucial to deliver steady stream of climate‐smart crop cultivars for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Genomic selection (GS) can substantially reduce breeding cycle times in forest trees compared to traditional breeding cycles. Practical implementation of GS in tree breeding requires an assessment of significant drivers of genetic gains over time, which may differ among species and breeding objectives. We present results of a GS study of growth and wood quality traits in an operational Eucalyptus grandis breeding program in South Africa. The training population consisted of 1575 full and half-sib individuals, genotyped with the Eucalyptus (EUChip60K) SNP chip resulting in 15,040 informative SNP markers. The accuracy of the GS models ranged from 0.47 (diameter) to 0.67 (fibre width). We compared a 4-year GS breeding cycle equivalent to half of a traditional 8-year E. grandis breeding cycle and obtained GS efficiencies ranging from 1.20 (wood density) to 1.62 (fibre length). Simulated over 17 years, the ratio of the accumulated genetic gains between three GS cycles and two traditional breeding cycles ranged from 1.53 (diameter) to 3.35 (wood density). To realise these genetic gains per unit time in E. grandis breeding, we show that significant adjustments have to be made to integrate GS into operational breeding steps. [ABSTRACT FROM AUTHOR]

Esta pesquisa objetivou estimar a eficiência da seleção precoce em clones de Eucalyptus “urograndis”. Para isto, avaliou-se um teste clonal de Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake localizado no município de Telêmaco Borba, PR. O diâmetro à altura do peito – DAP (centímetros) e altura – ALT (metros) foram mensurados aos três e aos nove anos e meio de idade. O experimento foi delineado em blocos completos casualizados com 68 tratamentos (Clones), sendo quatro testemunhas (materiais operacionais). Os ganhos foram estimados por meio dos valores genotípicos obtidos pelos BLUPs nas intensidades de seleção de 10% e 30%. Os componentes de variância, estimados via método REML, foram utilizados na estimação dos parâmetros genéticos. O coeficiente de herdabilidade média de clones ( ˆ2 c h ) para os caracteres mostrou-se semelhante (0,88 e 0,91 para DAP e 0,72 e 0,89 para H aos três e nove anos e meio, respectivamente) nas duas idades avaliadas e superior ao coeficiente de herdabilidade no sentido amplo ( ˆ2 g h ). Os ganhos genéticos variaram de 3,25% para H a 20,58% para DAP aos três anos. A eficiência da seleção precoce – ESP chegou a 100%, mostrando-se eficaz. As correlações genotípicas ( ˆ gr ) variaram entre 0,64 (DAP aos três anos x H aos nove anos e meio) a 0,79 (DAP aos três anos x H aos três anos). Desse modo, recomenda-se realizar a seleção precoce aos três anos de idade para ambas as intensidades de seleção, o que proporcionará então, ganhos muito próximos aos da seleção direta. This research aimed to estimate the early selection efficiency in clones of Eucalyptus “urograndis”. So, a clonal test of Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake located in the city of Telêmaco Borba, PR, was evaluated. The diameter at breast height – DBH (centimeters) and height – H (meters) were measured at three and nine and a half years of age. The experiment was a randomized block design with 68 treatments (Clones), four of which were the control (operational material). The gains were estimated using the genotypic value obtained by BLUPs at selection intensities of 10% and 30%. The average heritability of clones ( ˆ2 c h ) for the characteristics were similar (0.88 e 0.91 for DBH and 0.72 e 0.89 for H at three and nine and a half years of age, respectively) at the two evaluated ages and greater than broad sense heritability ( ˆ2 g h ). The efficiency of early selection – ESP reached values of 100%, proving to be effective. Genotypic correlations ( ˆ gr ) ranged from 0.64 (DBH at three years x H at nine years and a half) to 0.79 (DBH at three years x H at three years). Thus, it is recommended to perform the early selection at three years of age for both selection intensities, providing gains very close to those of the direct selection.

ABSTRACT This study aimed to estimate the genetic parameters, genetic correlations, genetic dissimilarity, and predicted gains with the selection of interspecific apomictic Paspalum plicatulum × Paspalum guenoarum hybrids in relation to seed yield traits. Nineteen genotypes that showed increased forage yield in previous studies were planted in a randomized complete block design with ten blocks. Traits evaluated in this study were: number of tillers/plant, number of reproductive tillers/plant, number of racemes/inflorescence, number of seeds/inflorescence, weight of a thousand seeds, and seed yield. Data were analyzed using a mixed model approach. The genotypes evaluated in our study showed improvement potential in relation to high heritability (H a 2 > 0.50 ), high precision (Acgen> 90%), and genetic dissimilarity (forming three groups) for seed yield traits. Seed yield showed high correlation to reproductive tillers that can be used as indirect selection tools for genetic improvement of seed yield.

A firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mango (Mangífera indica L.) is one of the main exotic fruits grown in Brazil, and is used as a component in various arrangements within production systems, where genetically improved cultivars are continually sought by producers to establish commercial plantations. The aim of this research therefore, was to describe the structure of variance (estimation) and mean values (prediction) in the classification and progressive selection of elite genotypes of the pink mango using the REML/BLUP procedure with a focus on mixed models. Twelve agro-technological variables were evaluated in twelve elite genotypes from three crops: 2010-2011, 2011-2012 and 2012-2013, in a completely randomised block design with six replications. Estimates of the repeatability coefficient were medium and high for most of the key attributes in the mango genetic breeding program: 0.83 for fruit weight, 0.91 for total soluble solids (SST), 0.51 for firmness, 0.93 for total titratable acidity (ATT), 0.92 for the SST/ATT ratio, and 0.767 pulp weight, and low (0.05) for percentage pulp. High genetic control was seen in the expression of the variables, and high mean stability in the repetition of the variable in successive cycles, with the exception of percentage pulp. As for percentage pulp, the most promising materials were the following, in decreasing order of future mean values: ‘CPAC 165’ (73.05), CPAC 329 (73.03), ‘Rosa 2’ (73.00), ‘Espada vermelha’ (72.98), ‘Rosa 36’ (72.97) and ‘P5Rosa’ (72.96), surpassing the control. This is a desirable attribute in the mango for both in natura consumption and industry. = A mangueira (Mangífera indica L.) é uma das principais fruteiras exóticas cultivadas no Brasil, sendo utilizada como um componente em vários arranjos dentro de sistemas produtivos, onde as cultivares geneticamente melhoradas são continuamente procuradas por parte dos produtores para a formação de plantios comerciais. Assim, objetivou-se com esta pesquisa descrever a estrutura de variâncias (estimação) e de médias (predição) na classificação e seleção progressiva de genótipos elites de manga rosa, empregando o procedimento REML/BLUP com enfoque em modelos mistos. Doze variáveis agrotecnológicas foram avaliadas em doze genótipos elites, em três safras: 2010-2011, 2011-2012 e 2012-2013, em delineamento experimental de blocos completamente casualizados, com seis repetições. As estimativas do coeficiente de repetibilidade foram medianos e altos para a maioria dos atributos chave do programa de melhoramento genético da mangueira: 0,83 para peso do fruto, 0,91 para sólidos solúveis totais (SST), 0,51 para firmeza, 0,93 para acidez total titulável (ATT), 0,92 para a relação SST/ATT, 0,767 peso da polpa e baixo (0,05) para porcentagem de polpa. Mostrando para essas variáveis alto controle genético na expressão das variáveis e grande estabilidade média na repetição do caráter em ciclos sucessivos, exceção feita para porcentagem de polpa. Quanto à porcentagem de polpa, os materiais mais promissores foram os seguintes, em ordem decrescente de médias futuras: CPAC 165 (73,05), CPAC 329 (73,03), Rosa 2 (73,00), Espada vermelha (72,98), Rosa 36 (72,97) e P5Rosa (72,96), superando a testemunha. Esse é um atributo desejável em manga tanto para o consumo in natura, quanto para a indústria.