CYTOGENETICAL AND BIOCHEMICAL ANALYSIS OF INTERSPECIFIC HYBRIDS BETWEE1'l VIGNA RADIATA AND V. UMBELLATA

Abstract

Interspecific hybrids were raised between V. radiata and V. umbellata. Both the species exhibit genotypic differences for crossability which can be exploited to have more number of vigorous hybrid seeds. The crossability percentage varied between 3.8 to t5.2 among different genotypes. The application of 4 ppm NAA was observed to enhance the foliage and pod set percentage. The hybrids were identified at the early stage by their mode of germination and twiny habit. Cytologically, the hybrids include an array of meiotic abnormalities ranging from non-pairing of chromosomes through the presence of univalents, chain and ring multivalents and laggards at anaphase-t. The codominant expression of species specific isoperoxidase at two development stages also characterized the interspecific hybrids.