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Maize grains are deficient in sulfur-containing amino acids such as methionine (Met) and cysteine (Cys). To date, no maize hybrid rich in Met and Cys has been commercialized particulalry in the subtropical regions. In this study, molecular characterization among seven inbreds using 89 SSRs grouped them into three clusters. The average genetic dissimilarity (GD) coefficient and gene diversity among these inbreds were 0.708 and 0.478, respectively. These seven inbreds were crossed in 7 × 7 half-diallel mating design, and the resulting 21 F 1 hybrids along with four popular hybrid checks were evaluated in three replications across three locations viz., Delhi, Vagarai and Gauria Karma. Genetic analysis revealed that additive gene action predominantly controls Met content, while, both additive and non-additive gene action are important for Cys. Met and Cys levels varied from 0.058 % to 0.306 % and 0.025–0.126 % with mean of 0.196 % and 0.060 %, respectively. Promising hybrids identified include MGU-MH-20 (Met: 0.306 %, Cys: 0.040 %, grain yield: 8136 kg ha−1), MGU-MH-17 (Met: 0.269 % Cys: 0.045 %, grain yield: 8178 kg ha−1), MGU-MH-19 (Met: 0.254 %, Cys: 0.048 %, grain yield: 8588 kg ha−1), and MGU-MH-18 (Met: 0.253 %, Cys: 0.034 %, grain yield: 9812 kg ha−1). No correlation was observed among Met, Cys, grain yield and GD. This study is the first to examine the genetics of Met and Cys accumulation in maize kernels. Our findings provide valuable insights for the development of high Met and Cys maize cultivars, which are vital to mitigate malnutrition, especially in developing countries. [Display omitted] • Analysis with 89 SSRs reveals that seven maize inbred lines are genetically diverse. • Genetic analysis reveals predominance of additive gene action for methionine (Met). • While, both additive and non-additive gene action were important for cysteine (Cys). • Met and Cys content varied from 0.058 % to 0.306 % and 0.025–0.126 %, respectively. • Experimental hybrids rich in Met and Cys with good grain yield were identified. [ABSTRACT FROM AUTHOR]

SUMMARY: Linking genotype with phenotype is a fundamental goal in biology and requires robust data for both. Recent advances in plant‐genome sequencing have expedited comparisons among multiple‐related individuals. The abundance of structural genomic within‐species variation that has been discovered indicates that a single reference genome cannot represent the complete sequence diversity of a species, leading to the expansion of the pan‐genome concept. For high‐resolution forward genetics, this unprecedented access to genomic variation should be paralleled and integrated with phenotypic characterization of genetic diversity. We developed a multi‐parental framework for trait dissection in melon (Cucumis melo), leveraging a novel pan‐genome constructed for this highly variable cucurbit crop. A core subset of 25 diverse founders (MelonCore25), consisting of 24 accessions from the two widely cultivated subspecies of C. melo, encompassing 12 horticultural groups, and 1 feral accession was sequenced using a combination of short‐ and long‐read technologies, and their genomes were assembled de novo. The construction of this melon pan‐genome exposed substantial variation in genome size and structure, including detection of ~300 000 structural variants and ~9 million SNPs. A half‐diallel derived set of 300 F2 populations, representing all possible MelonCore25 parental combinations, was constructed as a framework for trait dissection through integration with the pan‐genome. We demonstrate the potential of this unified framework for genetic analysis of various melon traits, including rind color intensity and pattern, fruit sugar content, and resistance to fungal diseases. We anticipate that utilization of this integrated resource will enhance genetic dissection of important traits and accelerate melon breeding. Significance Statement: Pan‐genomes aim to address the abundance of genome structural variation within species for improved genomic analyses. A new pan‐genome, constructed from de novo genome assemblies of 25 diverse melon (Cucumis melo L.) accessions, is integrated with a half‐diallel derived set of 300 F2 populations representing all possible parental combinations. The potential of this unified multi‐parental trait‐dissection framework for melon genetics and breeding is presented. [ABSTRACT FROM AUTHOR]

Genetics and crop improvement aspects of medicinal plants in Ashwagandha should be taken consideration to meet the accelerating pharmaceutical demands. For a better understanding of the genetic basis of root yield and related traits, a 9 × 9 diallel analysis excluding the reciprocals was carried out using SKA 27, SKA 11, SKA 6, SKA 24, SKA 10, SKA 26, JA 20, JA 134 and AWS 1 as parents. The σ2gca/σ2sca denotes that the majority of the traits considered except plant height and the number of secondary branches were governed by non-additive gene action. The fresh root yield was governed by almost equal proportions of additive and non-additive gene actions with a slight increment in additive proportion. Even though none of the parents was a good general combiner for all the traits considered, SKA 27 and SKA 11 appeared to be the best general combiners for root traits. The crosses JA 20 × AWS 1, SKA 24 × SKA 26 and JA 134 ×AWS 1 were found to be appropriate for the heterosis breeding on the basis of the estimates of SCA effects.

Six mungbean parental lines and their fifteen F1s produced from half-diallel mating design were investigated for combining ability and heterosis in terms of a yield and its components. Results showed highly significant variations among the parents and F1s, suggesting a wide genetic variability for the studied characters. Analysis of variance indicated that genotypes mean square values, general combining ability (GCA) and specific combining ability (SCA) were highly significant (p ≤ 0.001) for all measured traits except for days to flowering, days to maturity, and pod length indicating genetic diversity of parents and both additive and non-additive gene effects in the inheritance of the measured traits. A higher effect of SCA than GCA for plant height and seeds per pod suggests the preponderance of non-additive gene effects in the expression of characters. Based on per se performance and GCA, BARI Mung-1, PS-7, and BMXK1-14004 were the best general combiners for yield per plant. In the context of SCA, hybrids BMXK1-14004 × Sonali mung, BMXK1-14004 × PS-7, BMXK1-14004 × BINA Mung-8, Sukumar × PS-7, and BARI Mung-1 × BINA Mung-8 were good specific combiners. BMXK1-14004 × Sonali mung and BMXK1-14004 × PS-7 were the best heterotic hybrids for yield and yield-contributing traits. These parents and crosses could be utilized for further use in breeding programs to improve yields in mungbean crops. [ABSTRACT FROM AUTHOR]

In the present study, heterobeltiosis and standard heterosis were estimated on 36 F1s obtained through half-diallel mating design for yield and quality traits. For yield per plant trait, seven out of 36 hybrids recorded standard heterosis of more than 100 per cent. CSR-30 x HUBR10-9 (160.09 per cent) recorded the highest significant positive standard heterosis over yield check Pusa Basmati-1. For quality traits, hybrid Pusa Basmati-1121 X Pusa Basmati-1509 performed well, as it exhibited a significant desirable standard heterosis for kernel length, kernel length after cooking, kernel breadth after cooking, and length/breadth ratio. Other hybrids that performed well for quality traits were Pusa Basmati-1 X Pusa Basmati-1121, Type-3 X Pusa Basmati-1121, Type-3 X Pusa Basmati-1509 and Taraori Basmati X Pusa Basmati-1121. 17 hybrids were found to have the desired intermediate range of amylose content (20-25 per cent) and 22 hybrids showed a desirable range of 4-7 for alkali spreading value, based on per se performance.

The objectives focuses on estimation of the magnitude of heterosis for seed yield and its component traits taking an example of six diverse lines (Pure and Stable) of sweet pepper (red color) which were attempted in half-diallel fashion excluding reciprocals during Kharif 2017 and evaluated with a cultivar Bombay grown in a greenhouse with natural ventilation. The analysis of variance showed significant differences among parents and crosses for all traits studied. On the basis of heterosis studies, RSPUHF-3 × RSPUHF-2 and RSPUHF-4 × RSPUHF-2 were identified highly significant cross combinations over better parent and standard check for the number of seeds per fruit, seed weight per fruit, thousand seed weight and per cent seed recovery, whereas; the crosses RSPUHF-7 × RSPUHF-1 and RSPUHF-7 × RSPUHF-4 exhibited a higher standard heterosis for seed yield per plant. This study showed a desirable heterosis over better parent and standard check for seed yield and contributing traits and can further directly be identified as a superior F1s after their validation over different seasons for growing under protected environments or may be utilized in future breeding programmes to obtain desirable segregants for the development of trait specific superior genotypes.

Heterosis, the superiority of hybrids over their parents, is a major genetic force associated with plant fitness and crop yield enhancement. We investigated root-mediated yield heterosis in melons (Cucumis melo) by characterizing a common variety grafted onto 190 hybrid rootstocks, resulting from crossing 20 diverse inbreds in a diallel-mating scheme. Hybrid rootstocks improved yield by more than 40% compared with their parents, and the best hybrid yield outperformed the reference commercial variety by 65% under both optimal and minimal irrigation treatments. To characterize the genetics of underground heterosis we conducted whole genome re-sequencing of the 20 founder lines, and showed that parental genetic distance was no predictor for the level of heterosis. Through inference of the 190 hybrid genotypes from their parental genomes, followed by genome-wide association analysis, we mapped multiple quantitative trait loci for root-mediated yield. Yield enhancement of the four best-performing hybrid rootstocks was validated in multiple experiments with four different scion varieties. Our grafting approach is complementary to the common roots genetic approach that focuses mainly on variation in root system architecture, and is a step towards discovery of candidate genes involved in root function and yield enhancement. [ABSTRACT FROM AUTHOR]

Six mungbean parental lines and their fifteen F1s produced from half-diallel mating design were investigated for combining ability and heterosis in terms of a yield and its components. Results showed highly significant variations among the parents and F1s, suggesting a wide genetic variability for the studied characters. Analysis of variance indicated that genotypes mean square values, general combining ability (GCA) and specific combining ability (SCA) were highly significant (p ≤ 0.001) for all measured traits except for days to flowering, days to maturity, and pod length indicating genetic diversity of parents and both additive and non-additive gene effects in the inheritance of the measured traits. A higher effect of SCA than GCA for plant height and seeds per pod suggests the preponderance of non-additive gene effects in the expression of characters. Based on per se performance and GCA, BARI Mung-1, PS-7, and BMXK1-14004 were the best general combiners for yield per plant. In the context of SCA, hybrids BMXK1-14004 × Sonali mung, BMXK1-14004 × PS-7, BMXK1-14004 × BINA Mung-8, Sukumar × PS-7, and BARI Mung-1 × BINA Mung-8 were good specific combiners. BMXK1-14004 × Sonali mung and BMXK1-14004 × PS-7 were the best heterotic hybrids for yield and yield-contributing traits. These parents and crosses could be utilized for further use in breeding programs to improve yields in mungbean crops.

A study was conducted for the analysis of combining ability of some yield and quality taits in a set of 10 durum wheat genotypesfollowing a diallel mating design excluding reciprocals. The analysis of variance for combining ability revealed that mean square values due to parents and hybrids were significant for the traits days to 50% heading, days to maturity, plant height, number of effective tillers per plant, length of main spike, peduncle length, number of spikelets per main spike, grain yield per main spike, grain yield per plant, test weight, biological yield per plant, harvest index, specific sedimentation volume, protein content, sedimentation value and β carotene which revealed that existence of differences among the parents and hybrids. Significance of both 2GCA and 2SCA for the characters days to 50% heading, days to maturity, length of main spike and number of spikelets per main spike suggested that importance of both additive and non-additive gene effects for the inheritance of these characters. The value of average degree of dominance was close to one for days to maturity and length of main spike which revealed complete dominance behaviour of interacting alleles for these characters. The parents GDW 1255, GW 2007-112 and GW 1 were good combiners for multiple traits viz., days to 50% heading, days to maturity, length of main spike, number of spikelets per main spike, number of grains per main spike and spike density in F1 generation. The crosses (give best crosses for grain yield) GW 2002-51 x GW 1 and GW 2007-77 x GW 1277 was good specific combiners for multiple traits along with grain yield in F1 generation and these crosses may be utilized in the development of high yielding progenies in durum wheat.

In addition to fresh and roasted pumpkin seeds used in human nutrition, they are used as an additive to bread, salami, sausage, mayonnaise and many food products because of their high protein content. The most common problem encountered in the cultivation of confectionary pumpkin is the lack of varieties with good seed yield and quality in the market. In this study, it was aimed to reveal the promising hybrids with superior characteristics by determining the yield and seed characteristics of the 13 pumpkin inbred lines (Cucurita pepo) and 74 hybrid lines which are obtained by crossing between inbred lines and two local varieties (3-Hatun Tirnagi and 4-Cercevelik) as control. As a result of the study, the highest positive correlation was found between seed thickness and 1000 seed weight and between seed length and seed width. The crosses of 31x34, 23x28, 13x23, 38x40, 29x37, 30x31 and 23x29, especially 40x29, in the positive region of both components showed superior performance compared to their parents in all parameters. These hybrids have emerged as promising crosses to develop the F1 hybrid confectionary pumpkin varieties. [ABSTRACT FROM AUTHOR]

Utilization of stress tolerant maize is the key to sustainable production and food security, and hence studies were conducted at Dirab Research Station, Riyadh, Saudi Arabia, from 2009 to 2010 to estimate General Combining Ability (GCA), Specific Combining Ability (SCA) and their interactions with environment. Non-reciprocal diallel crossing was performed among six inbreds. The inbreds, 15 F1 hybrids and two checks were evaluated in split plot design. Regulated irrigation commenced before tasselling and stopped before grain filling stage, using Food and Agriculture Organization (FAO) evaporation pan as guide. Water was applied when pan reading was at 50, 70 and 90 in. to create E1, E2 and E3 environments respectively. Data were analyzed using method 3 of Gardner and Eberhart. Analysis of variance showed highly significant variance (P ⩽ 0.01) among almost all sources of variation. High significance GCA and SCA observed revealed the importance of both additive and non-additive genetic actions, while low GCA/SCA implied importance of dominant effects of gene. Anthesis-silking interval (ASI) was the most affected trait by water deficit indicating that selection for tolerance could be based on short ASI. Performance per se of the genotypes reveals the importance of hybrids with P1 and P6 but failed to indicate their suitability as combiners. The KSU 6–47 had highest significant GCA for grain yield under E1 and E2. KSU 3–69 had the lowest significant negative GCA for days to tasselling, while cross KSU 6–47 × KSU 3–69 with high SCA for grain yield and 1000-kernel weight under all environments suggested their usefulness for improvement.

The identification of heterotic groups may provide an important advantage for hybrid eggplant (Solanum melongena) breeding. In this study, we evaluated the combining ability and heterotic patterns of eggplant lines in order to develop improved eggplant cultivars resistant to Fusarium oxysporum f. sp. melongenae (FOM). A set of 62 inbred lines was evaluated with 32 morphological descriptors and their relationships were analyzed through a multivariate cluster analysis. A subset of 39 inbred lines was selected and, together with 15 sister lines, they were crossed with two testers to investigate their general combining ability (GCA) and to establish heterotic groups. Twenty selected inbred lines with high GCA were intercrossed using a half-diallel mating design. Eighty-two hybrids were obtained and evaluated for yield and yield components. We found no association between morphological distance and membership to specific heterotic groups. However, heterosis for yield was found in hybrids among parents from different heterotic groups or that were included in all heterotic groups. Among the hybrids evaluated, some were found to be highly productive and resistant to FOM, being candidates for the registration of new cultivars with dramatically improved characteristics.

Abstract: This study was aimed to determine gene action for grain yield and yield‐related traits of newly developed tef populations under drought‐stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F2 generation under drought‐stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield‐related traits under drought‐stressed and nonstressed conditions. Under both test conditions, the genotypes DZ‐Cr‐387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ‐Cr‐387 × 222076 was selected for high grain yield and early maturity in both the drought‐stressed and nonstressed environments. [ABSTRACT FROM AUTHOR]

A study was conducted during two crop season (Kharif, 2011-12 and 2012-13) for estimating the genetic parameters by involving 10 parents and their 45 F1s in rice crop. The estimates of h2 (overall dominance effects) were positive and significant for days to 50% flowering (9.11), days to maturity (0.24), plant height (2.95), panicle length1(39), productive tillers per plant (3.22), branches per panicle (5.61), flag leaf area (5.50), 1000-grain weight (0.27), biological yield (7.35) and amylose content (1.03) which indicated dominance of genetic components in F1s crosses. The theoretical value (0.25) of (H2/4H¹) for all the traits except kernel length and amylose content indicated the asymmetrical distribution of positive and negative genes in the parents. The proportion of dominant and recessive alleles for panicle length, productive tillers, branches per panicle, 1000 grain weight, biological yield, kernel length and L/B ratio reflected more dominant alleles, whereas for days to 50% flowering, days to maturity, plant height, grains per panicle, flag leaf area, grain yield, harvest index, kernel breadth, kernel length after cooking, elongation ratio, amylose content and hulling %, reflected more recessive alleles in the parents. The estimates of specific combining ability (SCA) effects revealed that the cross Vallabh Basmati 21 x Pusa 1121 could be an excellent candidate for improving grain yield (1.52**), harvest index (1.86**) and flag leaf area (6.20**) whereas Pusa 1121 x CSR 10 is excellent candidate for panicle length (0.89**) and amylose content (1.54**). The characters showing more than 60% narrow sense heritability along with positive and significant correlation with each other and also with grain yield could be rewarding for further improvement of yield and quality in rice. Therefore, these parental lines can be used as donors in future by following bi-parental mating and the diallel selective mating system could be the best breeding method in an early segregating generation for improvement in these traits in rice crop. [ABSTRACT FROM AUTHOR]

Utilization of stress tolerant maize is the key to sustainable production and food security, and hence studies were conducted at Dirab Research Station, Riyadh, Saudi Arabia, from 2009 to 2010 to estimate General Combining Ability (GCA), Specific Combining Ability (SCA) and their interactions with environment. Non-reciprocal diallel crossing was performed among six inbreds. The inbreds, 15 F 1 hybrids and two checks were evaluated in split plot design. Regulated irrigation commenced before tasselling and stopped before grain filling stage, using Food and Agriculture Organization (FAO) evaporation pan as guide. Water was applied when pan reading was at 50, 70 and 90 in. to create E1, E2 and E3 environments respectively. Data were analyzed using method 3 of Gardner and Eberhart. Analysis of variance showed highly significant variance ( P ⩽ 0.01) among almost all sources of variation. High significance GCA and SCA observed revealed the importance of both additive and non-additive genetic actions, while low GCA/SCA implied importance of dominant effects of gene. Anthesis-silking interval (ASI) was the most affected trait by water deficit indicating that selection for tolerance could be based on short ASI. Performance per se of the genotypes reveals the importance of hybrids with P1 and P6 but failed to indicate their suitability as combiners. The KSU 6–47 had highest significant GCA for grain yield under E1 and E2. KSU 3–69 had the lowest significant negative GCA for days to tasselling, while cross KSU 6–47 × KSU 3–69 with high SCA for grain yield and 1000-kernel weight under all environments suggested their usefulness for improvement. [ABSTRACT FROM AUTHOR]

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A set of seven promising inbred lines were involved in half-diallel mating design to study the combining ability effects for grain yield and yield contributing characters. The experimental material consisted of seven parents and their 21 crosses along with five public/private checks. Yield trials were conducted at three environments during Kharif 2015. Mean squares due to environments were highly significant for all the traits except kernels row-1 indicating that these traits were highly influenced by environment factors. Hybrids × environment and hybrids Vs parents × environment interaction was significant for ear length, grain yield and fodder yield. GCA × environment and SCA × environment (P < 0.05) interactions were significant for plant height, ear length and fodder yield traits. The magnitude of the interaction of SCA × environments is higher than GCA × environments for flowering and maturity traits, kernel rows ear-1, shelling %, 100 kernel weight, grain yield for combined analysis over three environments. GCA/SCA ratio was less than unity for all the studied traits indicating non additive gene action plays a major role in controlling the traits. Across the environments, BML-51 was a good general combiner for days to 75% dry husk, plant height, ear height, ear length, shelling %, 100 kernel weight, grain yield and fodder yield. BML-13 and BML-10 were good general combiners for flowering traits. Among the crosses, BML-51 × BML-14 had significant and positive SCA effects with high mean values in all three environments and pooled over environments for grain yield and fodder yield. [ABSTRACT FROM AUTHOR]

The present investigation entitled "Identification of promising heterotic combinations for yield and yield attributed traits in Indian mustard [Brassica juncea (L.) Czern & Coss]" consists analysis of 15×15 half-diallel set of crosses in Indian mustard revealed that non-additive gene effects was found to be predominant for secondary branches per plant, whereas preponderance of additive gene effects for the inheritance of rest of the characters. The evaluation of heterosis revealed that PRB-2004-3-4×PRE-2009-9(-9.627**), Bhaghirathi ×PRE-2009-9 (-16.53**), RGN-145×PR-2006-1(-4.64**) for early maturity, PRB-2008-5× PRB-2004-3-4 (-24.37**), PRB-2008-5×PRE-2009-9 (-24.89**), PRE-2009-9×NDYR-8 (-23.32**) for dwarf plant height, PR-2006-1×NDRE-4 (201.74**), PR-2006-1×NDYR-8 (137.26**), Maya×PRE-2004-3-4 (40.26**) for seed yield, PRE-2009-9×NDYR-8 (15.84**), RGN-74×PRE-2007-6 (2.91**), Maya×NDYR-8 (2.09**) for oil content, most promising were heterotic crosses for mid parent heterosis, better parent and economic heterosis respectively. All three type of heterosis with respect to over mid parent, better parent and standard check were observed significant in desirable direction for all the characters except glucosinolate content. The manifestation of high amount of heterosis for seed yield and component traits by a large number of crosses suggesting need to maintain heterozygosity in the population for maximum expression of traits in desirable direction. Foregoing results and inferences revealed that the presence of wide spectrum of exploitable variability in research material studied with respect to various quantitative traits projecting, thereby, immense scope for genetic improvement in Indian mustard. Therefore, with the help of heterosis studies, the superior cross combination of promising hybrids could be identified for developing high yielding cultivars. [ABSTRACT FROM AUTHOR]

Gladiolus Sylvia x Melody exhibited early corm-sprouting (6.82 days). The hybrid Melody x Summer Sunshine (84.63 cm), followed by American Beauty x Pricella (84.12 cm) were tall. Maximum stem girth was observed in American Beauty x Summer Sunshine (35.31 mm), followed by Vedanapoli x Magic (33.71mm) and American Beauty x Melody (33.47 mm). Number of leaves per plant was higher in Melody x Magic (9.62), followed by Salvia x Magic (9.49) and Melody x Vedanapoli (9.42). The length was maximum (67.32 cm) in Melody x Summer Sunshine followed by Summer Sunshine x Pricella (67.57 cm), American Beauty x Vedanapoli (67.00 cm) and Vedanapoli x Pricella (66.06 cm). The hybrid Salvia x Melody was earliest to initiate flower bud (60.58 days) and first floret opening (69.04 days). The total duration of flowering was maximum in Vedanapoli x Magic.

The inheritance of Fusarium head blight (FHB) resistance was investigated in eight western European wheat lines using a half-diallel of F1 crosses. The parents and F1 crosses were point-inoculated, with a highly aggressive isolate of Fusarium graminearum, in replicated field and glasshouse trials. Type II resistance was assessed by measuring the % FHB spread and % wilted tips. There was a good correlation between the two disease parameters, % FHB spread area under the disease progress curve (AUDPC) and % wilted tips AUDPC ( r = 0.86, P < 0.01). Correlation coefficients between the field and glasshouse environments were r = 0.46 ( P < 0.01) for % FHB spread AUDPC and r = 0.40 ( P < 0.05) for % wilted tips AUDPC. Both general combining ability (GCA) and specific combining ability (SCA) effects influenced the inheritance of FHB resistance, suggesting that in this set of parents both additive and non-additive (dominance or epistatic) effects influence the inheritance of type II FHB resistance. Highly significant GCA-by-environment ( P < 0.0001) and SCA-by-environment ( P < 0.005) interactions were also observed. Specific combinations of western European wheat varieties were identified with type II FHB resistance at a level equal to or more resistant than the winter wheat variety ‘Arina’. [ABSTRACT FROM AUTHOR]

Crop breeding involves two selection steps: choosing progenitors and selecting individuals within progenies. Genomic prediction, based on genome-wide marker estimation of genetic values, could facilitate these steps. However, its potential usefulness in grapevine (Vitis vinifera L.) has only been evaluated in non-breeding contexts mainly through cross-validation within a single population. We tested across-population genomic prediction in a more realistic breeding configuration, from a diversity panel to ten bi-parental crosses connected within a half-diallel mating design. Prediction quality was evaluated over 15 traits of interest (related to yield, berry composition, phenology and vigour), for both the average genetic value of each cross (cross mean) and the genetic values of individuals within each cross (individual values). Genomic prediction in these conditions was found useful: for cross mean, average per-trait predictive ability was 0.6, while per-cross predictive ability was halved on average, but reached a maximum of 0.7. Mean predictive ability for individual values within crosses was 0.26, about half the within-half-diallel value taken as a reference. For some traits and/or crosses, these across-population predictive ability values are promising for implementing genomic selection in grapevine breeding. This study also provided key insights on variables affecting predictive ability. Per-cross predictive ability was well predicted by genetic distance between parents and when this predictive ability was below 0.6, it was improved by training set optimization. For individual values, predictive ability mostly depended on trait-related variables (magnitude of the cross effect and heritability). These results will greatly help designing grapevine breeding programs assisted by genomic prediction., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved.)

Clones of Lolium perenne L., chosen as sensitive or tolerant to sulphur dioxide (SO2) injury, were employed in a half-diallel crossing programme to carry out an analysis of the genetic basis of tolerance to acute SO22 concentrations. Their progeny were fumigated with SO2 and the percentage injury on the foliage scored and subjected to an analysis of variance designed to test an additive dominance model. The genetic analysis indicated that dominance was towards SO2 susceptibility. Further analysis of the relationship between variance and covariance of members of the same parental array supported this finding and suggested that only a few genes were involved. The results show clearly that the relative sensitivity of L. perenne to acute SO2 concentrations is heritable, with significant additive and non-additive components. A comparison with the very limited number of other studies on the genetic basis of SO2 tolerance, suggests that it is highly variable between species. [ABSTRACT FROM AUTHOR]

Computer simulation was used to compare minimum variance quadratic estimation (MIVQUE), minimum norm quadratic unbiased estimation (MINQUE), restricted maximum likelihood (REML), maximum likelihood (ML), and Henderson's Method 3 (HM3) on the basis of variance among estimates, mean square error (MSE), bias and probability of nearness for estimation of both individual variance components and three ratios of variance components. The investigation also compared three procedures for dealing with negative estimates and included the use of both individual observations and plot means as the experimental unit of the analysis. The structure of data simulated (field design, mating designs, genetic architecture and imbalance) represented typical analysis problems in quantitative forest genetics. Results of comparing the estimation techniques demonstrated that: estimates of probability of nearness did not discriminate among techniques; bias was discriminatory among procedures for dealing with negative estimates but not among estimation techniques (except ML); sampling variance among estimates was discriminatory among procedures for dealing with negative estimates, estimation techniques and unit of observation; and MSE provided no additional information to variance of the estimates. HM3 and REML were the closest competitors under these criteria; however, REML demonstrated greater robustness to imbalance. Of the three negative estimate procedures, two are of practical significance and guidelines for their application are presented. Estimates from individual observations were always preferable to those from plot means over the experimental levels of this study. [ABSTRACT FROM AUTHOR]

The identification of heterotic groups may provide an important advantage for hybrid eggplant (Solanum melongena) breeding. In this study, we evaluated the combining ability and heterotic patterns of eggplant lines in order to develop improved eggplant cultivars resistant to Fusarium oxysporum f. sp. melongenae (FOM). A set of 62 inbred lines was evaluated with 32 morphological descriptors and their relationships were analyzed through a multivariate cluster analysis. A subset of 39 inbred lines was selected and, together with 15 sister lines, they were crossed with two testers to investigate their general combining ability (GCA) and to establish heterotic groups. Twenty selected inbred lines with high GCA were intercrossed using a half-diallel mating design. Eighty-two hybrids were obtained and evaluated for yield and yield components. We found no association between morphological distance and membership to specific heterotic groups. However, heterosis for yield was found in hybrids among parents from different heterotic groups or that were included in all heterotic groups. Among the hybrids evaluated, some were found to be highly productive and resistant to FOM, being candidates for the registration of new cultivars with dramatically improved characteristics. [ABSTRACT FROM AUTHOR]