No abstract

Plant viral diseases are one of the major limitations in legume production within sub Saharan Africa (SSA), as they account for up to 100 % in production losses within smallholder farms. In this study, field surveys were conducted in the western highlands of Kenya with viral symptomatic leaf samples collected. Subsequently, next-generation sequencing was carried out. The main aim was to gain insights into the selection pressure and evolutionary relationships of Bean common mosaic necrosis virus (BCMNV) and Cowpea aphid-borne mosaic virus (CABMV), within symptomatic common beans and cowpeas. Eleven near complete genomes of BCMNV and two for CABMV sequences were obtained from SSA. Bayesian phylogenomic analysis and tests for differential selection pressure within sites and across tree branches of the viral genomes was carried out. Three distinct well-supported clades were identified across the whole genome tree, and were in agreement with individual gene trees. Selection pressure analysis within sites and across phylogenetic branches suggested both viruses were evolving independently, but under strong purifying selection, with a slow evolutionary rate. These findings provide valuable insights on the evolution of BCMNV and CABMV genomes and their relationship to other viral genomes globally. These results will contribute greatly to the knowledge gap surrounding the phylogenomic relationship of these viruses, particularly for CABMV, for which there are few genome sequences available, and support the current breeding efforts towards resistance for BCMNV and CABMV.

This paper describes the findings of a study that used a multi‐market model to assess the potential impact of improved maize technologies on the welfare of various types of rural and urban households in Kenya. The modelling results indicate that technologies developed for high potential regions are likely to have more profound aggregate impacts on maize production and lead to greater reductions in import demand (if prices are controlled) or maize prices (if maize prices are flexible). Technology adoption in high potential regions is likely to have substantially greater positive impacts on aggregate real incomes, but inferior income distributional outcomes compared to technology adoption in marginal regions.

Sixteen progeny lines of common beans obtained from single crosses made between two parents, GLP2 and KAT B1, were grown in randomized complete block design in a rainout shelter at the Agricultural and Mechanization Research Institute, Machakos, Kenya. e experiment was conducted to study inheritance of traits associated with drought stress adaptation and to establish if significant variation for those traits was existing in order to carry out selection for drought tolerance. e calculated mean values were used to estimate heritability, genetic advance, and correlation study for each trait. Water stress had a significant (p ≤ 0.01) effect on the number of pods per plant, grains per plant, 100-seed weight, and yield per plant. e highest values for genotypic coefficient of variation (36.11%) and phenotypic coefficient of variation (36.70%) were recorded for pods plant -1 under stress condition. Highest broad-sense heritability estimates (96.54%, 94.97%, and 93.16%) coupled with high genetic advance as percent of the mean (22.32%, 34.97%, and 26.32%) were obtained for the number of pods plant − 1 , days to maturity, and yield plant − 1 , respectively, showing that selection of these traits together could lead to yield improvement under stressed conditions. Harvest index showed a significant and positive relationship with biomass aboveground (r � 0.86) and the number of pods plant − 1 (r � 0.86) indicating the possibility of identifying high performing lines of common beans for drought stress environment for further studies on these traits.

Participatory variety selection (PVS) is the selection of new varieties among fixed lines by farmers under different target environments. It is increasingly being used to select and promote new crop breeding materials in most African countries. A gender-responsive PVS tool was piloted in Embu and Nakuru in the first and second cropping seasons of 2019 to understand similarities and differences between men’s and women’s varietal and trait preferences for biofortified released varieties and local bean varieties (landraces). Pooled results indicate that varietal and trait preferences between men and women farmers were slightly different but followed gendered roles and division of labor. Women farmers have a higher preference for landraces compared to men due to their availability, affordability and accessibility. Preferences for bean varieties differed between men and women across the two counties. High yielding was the most prioritized trait by both men and women for Mwitemania, Nyota, and Angaza. The findings support the long-held assumption that men prefer market-oriented traits, but women have a greater range of concerns thus less market oriented than men. For Nyota, men’s preferences were shaped by market traits, while women’s preferences were based on the variety being early maturing, resistant to pests and diseases, marketable, and fast cooking. For other varieties, men preferred Mwitemania because it is high yielding, early maturing, resistant to pests and diseases, and marketable. In contrast, women preferred Mwitemania because of seed availability, fast cooking, and early maturing. However, men’s and women’s varietal preferences for Angaza were similar, with them reporting early maturing, resistance to pests and diseases, and marketability as attractive traits. Sociodemographic characteristics such as education, age, marital status, and land ownership underlined the differences in trait preferences. Despite having attractive traits for both men and women, Nyota increased drudgery, displaced women from their usual activities, and required additional inputs by women, signaling possible adoption tradeoffs. However, Nyota, Angaza, and Mwitemania can provide the opportunity to increase employment for women. This study calls for gender integration at the design stage of any breeding system to ensure men and women farmers have access to varieties they prefer for food and income generation.