Characterization of selected cowpea and sesame accessions at Genetic Resources Research Institute (GeRRI) in Kenya: Adding value to the rich collection

Abstract

Gene banking is the most cost-effective ex situ strategy for conserving plant genetic resources. It was developed for the storage of predominantly orthodox seeds. To maintain long-term seed survival and integrity of the conserved germplasm in the genebanks, seed viability testing and regeneration should be done occasionally. The seed viability tests inform which accessions need regeneration. In addition, adequate evaluation and characterization of the conserved germplasm enhances their wider utilization. The Genetic Resources Research Institute (GeRRI) in Kenya and Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) undertook a joint project entitled Improvement of Technology on Conservation of Genetic Resources from 2015 and 2018. Korea-Africa Food and Agriculture Cooperation Initiative was funding the project, while GeRRI was the implementing institution. One of the objectives was to carry out morphological characterization of sesame, millet and cowpea accessions conserved at GeRRI’s genebank to promote their conservation and utilization. A total of 376 accessions of two crops (216 cowpeas and 160 sesame) were withdrawn from the conservation unit at GeRRI’s genebank and characterized at KALRO’s Perkerra field site during the 2018 long rains season. About 78 % of the cowpea accessions had reached 50 % flowering within 60 days after planting. Over 80 % of sesame accessions yielded ≤ 400kg of seeds per hectare. Multivariate analyses were performed to establish similarity patterns. Principal Component Analysis (PCA) showed that four components had eigenvalues >1, accounting for 61.23 % of the total variability among the cowpea accessions. The first four PCs accounted for 63.95 % of the total variability for the sesame accessions. In addition, all the quantitative characters considered were important in describing phenotypic variation in these sesame accessions. The study has shown that there is wide variability among cowpea, as well as sesame accessions, conserved at GeRRI’s genebank. All the quantitative characters measured in this study were important in describing phenotypic variation among cowpea and sesame accessions.