Drought stress is becoming one of the most important abiotic factors limiting productivity of common bean (Phaseolus vulgaris L.) globally. The objective of this study was to conduct a quantitative trait loci (QTL) analysis of drought tolerance in a recombinant inbred line (RIL) mapping population genotyped using single nucleotide polymorphism (SNP) markers. The RIL population was developed by crossing Portillo × Red Hawk, two Andean bean genotypes contrasting in reaction to drought stress and evaluated at two locations in Uganda for two seasons under drought stress (DS) and non‐stress (NS) conditions. Eighteen significant QTL signals were identified for phenology, yield component and partitioning traits on chromosomes Pv01, Pv02, Pv03, Pv04, Pv06, and Pv11 under DS and NS conditions. Quantitative trait loci for seed yield per plant (SY) were detected on Pv01, Pv02, Pv03, Pv04, and Pv06 under DS conditions. Colocalized QTL signals for pod weight per plant and SY were identified under DS on Pv01 (45.15 Mb) and on Pv02 (0.12 Mb), for phenology and SY on Pv03 near marker ss715639424 (40.16 Mb), and for SY and harvest index on Pv06 (17.92 Mb). Two candidate genes related to flowering were identified within a 35‐kb region from the ss715639424 marker on Pv03. Gene Phvul.003G189100 (30.3 kb) encodes “AGAMOUS‐LIKE 65 (AGL65),” which is essential for pollen development, and gene Phvul.003G189300 (17.9 kb) encodes “CYCLING DOF FACTOR 3 (CDF3)” that regulates flowering time. The same SY QTL, SY3.3PR on Pv03, was previously detected in Mesoamerican germplasm and could be used through marker‐assisted breeding to improve SY of Andean beans grown under DS.

Common bean is the most important edible grain legume and dietary component in the world (Gepts et al., 2008). Bean contributes significantly to food and nutritional security of millions in sub-Saharan Africa and the developing world, providing a cheap protein source and micronutrients such as iron and zinc (Broughton et al., 2003; Graham et al., 2007), and income for smallholder farmers. However, productivity of common bean in many parts of Central and South America, and Africa is constrained by several diseases that includes root rots (RR) (Abawi and Corrales, 1990). Common bean RR caused by a complex of numerous soil-borne pathogenic fungi including Fusarium solani f. sp. phaseoli, Pythium spp., Rhizoctonia solani and Sclerotium rolfsii Sacc. are the primary cause of crop failures among subsistence farmers in the East African Region (Abawi and Corrales,

The use of molecular markers allows for precise estimates of genetic diversity, which is an important parameter that enables breeders to select parental lines and designing breeding systems. We assessed the level of genetic diversity and population structure in a panel of 151 tropical maize inbred lines using 10,940 SNP (single nucleotide polymorphism) markers generated through the DArTseq genotyping platform. The average gene diversity was 0.39 with expected heterozygosity ranging from 0.00 to 0.84, and a mean of 0.02. Analysis of molecular variance showed that 97% of allelic diversity was attributed to individual inbred lines within the populations while only 3% was distributed among the populations. Both neighbor-joining clustering and STRUCTURE analysis classified the inbred lines into four major groups. The crosses that involve inbred lines from most divergent subgroups are expected to generate maximum heterosis and produce wide variation. The results will be beneficial for breeders to better understand and exploit the genetic diversity available in the set of maize inbred lines we studied.

Often, yam cultivars grown in different agro-ecologies show differential responses across production environments, a term known as genotype-by-environment interaction. Such genotype-by-environment interaction makes selection of the best genotypes under varied production environments more complex. This study evaluated twenty yam genotypes in six test environments to assess genotype, environment, and their interaction effects on tuber yield, response to yam mosaic virus, and dry matter content. The experiments were conducted over two seasons across three locations in Uganda, using a randomized complete block design with three replications. There were significant effects (p ≤ 0.001) for genotype (G), environment (E), and genotype-by-environment interaction for all key traits assessed. Serere (2021) and Namulonge (2021) were identified as the most discriminating and representative environments for testing responses to yam mosaic virus, respectively. Serere (2021) was recognized as the most discriminating environment, whereas Arua (2021) emerged closest to an ideal environment for assessing yam tuber yield. The tested genotypes also exhibited resistance to yam mosaic virus disease, had high tuber yields and dry matter content. Genotypes UGY16020, UGY16034, UGY16042, and UGY16080 demonstrated highest resistance to yam mosaic virus disease, along with high yield and dry matter content, and are thus potential parents for yam genetic improvement. Further evaluation of the four genotypes should be carried out within farmers’ production systems for selection, improvement and release as new yam varieties for Uganda.