Cowpea is an important source of food and income for small scale farmers in Uganda. Production is, however, affected by both biotic and abiotic stresses. Drought stress has recently emerged as a serious concern due to the effects of climate change. This study was therefore undertaken to estimate the general and specific combining ability effects of parents and crosses as well as estimate the heritability of delayed leaf senescence, seed yield and its components under drought stress. Five drought tolerant genotypes were crossed with four drought sensitive genotypes in a North Carolina II mating design. The study revealed that drought tolerance is conditioned by both additive and non-additive genetic effects with the predominance of non-additive genetic effects for seed yield, 100 seed weight and number of pods per plant. Delayed leaf senescence was however, controlled by additive genetic effects, implying that progenies performance could be predicted from parents General Combining Ability (GCA) effects. The cultivars SECOW 5T, IT93K-452-1 and IT98K-205-8 were good combiners for drought tolerance. The F2 families: SECOW 3B x IT98K-205-8, SECOW 5T x IT98K-205-8, SECOW 4W x IT98K-205-8 and SECOW 1T x IT98K-205-8 had positive Specific Combining Ability(SCA) effects in seed yield, number of pods per plant and 100 seed weight, implying that they performed better than what was predicted by their parents GCA effect. As such, they are promising cross combinations that can be advanced for later generation selection.

Soybean (Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean accessions, therefore, evaluate soybean value in terms of use for breeding purposes. To accomplish this, a set of 282 soybean accessions were genotyped using the Diversity Array Technology Sequencing with a high throughput of the Single-nucleotide polymorphisms (SNPs). A total of 6,935 high-quality SNPs were identi ed across the whole soybean genome. The mean value of genetic diversity, major alleles frequency, minor alleles frequency, expected heterozygosity, and the polymorphism information content was respectively estimated at 0.35, 0.77, 0.22, 0.33, and 0.29. The analysis of molecular variance reveals that the variance among the populations is lower than the variance within the populations. The soybean accessions could be classi ed into two groups based on the model-based population structure and the principal coordinate analysis or into three groups based on the discriminant analysis of the principal component and the Neighbor-joining tree. The information provided in this study will be helpful for breeders.

Soybean (Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean accessions, therefore, evaluate soybean value in terms of use for breeding purposes. To accomplish this, a set of 282 soybean accessions were genotyped using the Diversity Array Technology Sequencing with a high throughput of the Single-nucleotide polymorphisms (SNPs). A total of 6,935 high-quality SNPs were identified across the whole soybean genome. The mean value of genetic diversity, major alleles frequency, minor alleles frequency, expected heterozygosity, and the polymorphism information content was respectively estimated at 0.35, 0.77, 0.22, 0.33, and 0.29. The analysis of molecular variance reveals that the variance among the populations is lower than the variance within the populations. The soybean accessions could be classified into two groups based on the model-based population structure and the principal coordinate analysis or into three groups based on the discriminant analysis of the principal component and the Neighbor-joining tree. The information provided in this study will be helpful for breeders.

Soybean (Glycine max (L.) is an important oil crop with production below the real need in Africa. To increase the production, substantial upgrading must be accomplished by enlarging the genetic potential of new cultivars that relays on the parents' genetic diversity. We aimed to assess the genetic diversity and the population structure of soybean accessions, therefore, evaluate soybean value in terms of use for breeding purposes. To accomplish this, a set of 282 soybean accessions were genotyped using the Diversity Array Technology Sequencing with a high throughput of the Single-nucleotide polymorphisms (SNPs). A total of 6,935 high-quality SNPs were identified across the whole soybean genome. The mean value of genetic diversity, major alleles frequency, minor alleles frequency, expected heterozygosity, and the polymorphism information content was respectively estimated at 0.35, 0.77, 0.22, 0.33, and 0.29. The analysis of molecular variance reveals that the variance among the populations is lower than the variance within the populations. The soybean accessions could be classified into two groups based on the model-based population structure and the principal coordinate analysis or into three groups based on the discriminant analysis of the principal component and the Neighbor-joining tree. The information provided in this study will be helpful for breeders.