Inheritance of resistance to three endemic viral diseases of cowpea in Nigeria

Abstract

Mosaic diseases, caused by bean common mosaic virus-blackeye cowpea mosaic strain (BCMV-BlCM), southern bean mosaic virus (SBMV) and cucumber mosaic virus (CMV), hamper the productivity of cowpea (Vigna unguiculata (L.) Walp.). Under single or mixed infections, these endemic viruses significantly reduce cowpea yield in sub-Saharan Africa.Virus infections were confirmed via antigen-coated plate enzyme-linked immunosorbent assay or reverse transcription-polymerase chain reaction. Chi-square analysis of the genetic segregation indicated that a recessive gene pair in IT97K-1042-3 controlled the inheritance of resistance to BCMV-BlCM. Duplicate dominant genes conditioned the resistance to SBMV and tolerance to CMV in IT98K-1092-1. The backcrosses confirmed the monogenic and digenic inheritance patterns, whereas reciprocal crosses indicated absence of cytoplasmic effects.