Inheritance Studies of Sterility Mosaic Disease (SMD) Resistance Cross Gullyal white×BSMR736 in Pigeonpea ( Cajanus cajan (L.) Millsp.)

Sterility mosaic disease (SMD) is a major problem of pigeonpea all over India and particularly in Karnataka, Maharashtra and parts of Andhra Pradesh. Pigeonpea yields have been declining due to heavy and recurring occurrence of the SMD in southern Karnataka and some districts of northern Karnataka. The occurrence of this disease in farmer's field is reported to vary between 0 and 100%. A comprehensive study of variability in the sterility mosaic pathogen has revealed the occurrence of five different isolates of the pigeonpea sterility mosaic virus in India. With this view in the background, the objective was undertaken in the present study. The nature of inheritance of SMD in resistant (BSMR736) and susceptible (Gullyal white) genotypes. SMD incidence observed in parents, Reaction of F 2:3 families of Gullyal whitexBSMR 736 cross. Out of 300 F 2:3 families field evaluated, 55 showed resistant phenotype, 209 were moderately resistant and 36 families were susceptible for PPSMV. A basic knowledge of inheritance and number of genes governing the traits are essential for efficient selection. The ratio of F 2:3 families to SMD were corroborated with respectively F 2 individual plant. cross Gullyal white×BSMR736 and governed by two genes designated as SV 1 and SV 2 . The dominant allele of one gene ( SV1 ) has inhibitory action on the character (resistance) govern by other ( SV2 ) gene. Based on these, the presence of dominant allele of SV1 gene in one locus suppresses the action of dominant allele of SV2 (resistance) gene present on another locus resulting in susceptible phenotype.