Screening chilli (Capsicum spp.) germplasm against Cucumber mosaic virus and Chilli veinal mottle virus and inheritance of resistance

Abstract

Cucumber mosaic virus (CMV) and Chilli veinal mottle virus (ChiVMV) are aphid-borne major destructive viruses affecting chilli crops. Identification of resistant sources and understanding the genetic behaviour of resistance is essential for resistance breeding. In this study, fifty Capsicum genotypes were screened for CMV and ChiVMV resistance through mechanical inoculation. Symptoms varying from chlorotic local lesions to severe leaf distortion were observed and among the genotypes eighteen immune, eight highly resistant, five resistant and two moderately resistant genotypes were identified against CMV. For ChiVMV, dark green vein banding to severe shoe string symptoms were observed and among genotypes, seventeen were immune, one highly resistant, five resistant and two moderately resistant. Ten parents were selected and crossed in diallel fashion without reciprocals to produce 45 F1 hybrids and were screened for resistance against both the viruses separately. Only one hybrid IHR 2451 x IHR 500 showed resistance against CMV and all resistant x resistant F1 hybrids i.e. IHR 4503 x IHR 2451, IHR 4503 x IHR 500, IHR 2451 x IHR 500, IHR 3849 x IHR 2451 and IHR 3849 x IHR 500 were found resistant against ChiVMV. Further the inheritance studies using advanced populations showed that the CMV resistance is polygenic recessive and ChiVMV resistance is monogenic recessive in IHR 2451 and IHR 4503.