The mode of inheritance of resistance to cowpea aphid-borne mosaic virus (CAMV) and southern bean mosaic virus (SBMV) was determined in the following cowpea (Vigna unguiculata s.sp. unguiculata (L) Walp) varieties: A44/2, TVu 222, TVu 612 all resistant to CAMV and TVu 1948, which is resistant to both CAMV and SBMV. Crosses were made between each of the resistant varieties and C20-55, a cowpea variety susceptible to CAMV and SBMV. The parents, FI, F2, B1 and B2 progenies of each cross were raised in the greenhouse and inoculated with the appropriate virus.
The results showed that two recessive genes control resistance to CAMV in A44/2, a single dominant gene controls resistance to the same virus in TVu 222, while a single recessive gene was responsible for resistance in each of the varieties TVu 612 and TVu 1948. Results of allelic tests among the F1 and F2 progenies of crosses among A44/2, TVu 612, and TVu 222 indicated that each of them possesses different genes for resistance to CAMV. Resistance to SBMV was under the control of a single dominant gene in TVu 1948.||en_US