Exploring New Sources of Viral Resistance in Cowpea Germplasm and Its Elaboration through Multivariate Analysis

Abstract

Background: Cowpea is a major food legume rich in protein but its production has been dwindling by several factors including viral infection due to various virus strains in all agro-ecological zones.Methods: Sixty eight cowpea genotypes were screened against qualitative traits (leaf shape, seed surface, twinning tendency, anthocynin pigment, plant type, fodder type and cream color) and four seed borne viruses viz. cucumber mosaic virus (CMV), cowpea aphid borne mosaic virus (CABMV), black eye cowpea mosaic virus (BlCMV) and bean common mosaic virus (BCMV) under both in situ and laboratory conditions using DAC-ELISA.Result: Based on in situ screening, 16 genotypes were found resistant to all the four viruses, whereas for ELISA, 13 genotypes (27005, 27041, 27075, 27141, 27145, 27146, 27147, 27158, 27160, 27167, 27172, IT85F-1380 and IT86D-719) were found resistant to all. Twelve clusters were obtained from UPGMA based on disease severity. Genotype 27008 (Pakistan) was present in cluster VI and was susceptible to all antisera CMV, CABMV, BICMV and BCMV. Whereas 13 genotypes were present in cluster VIII which were found resistant to all the four antisera applied. Therefore, 13 genotypes suggested for safe use in any breeding program at developing resistant cultivars. First two factors obtained through PCA with eigen-values greater than 1 contributed greater than 80 per cent variability. Twelve distinct groups were observed and these were in coordination with cluster analysis.