Radiation-Induced Instability at the Virescent Locus in Groundnut

A new case of instability induced in groundnut by T-irradiation was classified as a variegated mutation according to its phenotypic expression. The mutant was isolated in M₂ generation and segregated for 50% virescents in subsequent generations. Studies on the phenotypic and genetic behaviour of the mutant suggested that (i) a mutation was inducded at v-locus and its unstable expression further mutated to a stable recessive condition, i.e., virescence, (ii) another mutation for ga-metophyte factor was induced, probably, close to v-locus preventing transmission of V^m factor through the pollen, (iii) test crosses indicated that the variegation was controlled by a nuclear gene and not by plasmon.