Heritability and allelic relationship of Fusarium wilt resistance genes in cowpea genotypes cultivated in Burkina Faso

Cowpea is an important legume crop to farmers as a food, fodder, agronomic, and income-generating crop. Despite these multiple advantages, cowpea cultivation faces enormous abiotic and biotic constraints, including fungal diseases such as Fusarium wilt, caused by Fusarium solani (Mart.) Sacc. One of the control measures for this disease, which causes severe yield losses, is the use of resistant varieties. However, the genetics underlying the inheritance and gene action in the resistance of cowpea to F. solani are not well established. Hence, this study consisted of determining the inheritance of resistance and the allelic relationship of two cowpea genotypes (B301 and Tiligre) to F. solani. Parents and F1 and F2 offspring developed were evaluated in pots under artificial infestation in a greenhouse using a randomized design with three replications at the Kamboinse research station in Burkina Faso for their reaction to F. solani. Resistance of genotypes was assessed based on phenotypic vascular discoloration at 60 days after inoculation (DAI). Disease severity was assessed using a scale of six classes (0 to 5). The data were subjected to the Chi-Square goodness-of-fit test for one and two-gene segregation ratios. Studies on inheritance and allelic relationships showed that resistance is governed by a dominant gene in both genotypes (B301 and Tiligre). No allelic relationship between the genes in the two resistant cowpea genotypes was identified. The results obtained in the present study could be used in the cowpea breeding program in Burkina Faso. Key words: Cowpea, Fusarium solani, dominance, inheritance, allelism.