Genomic relationship in Vigna species

Abstract

Investigations on the genomic relationship in Vigna species were undertaken in the Department of Agricultural Botany, College of Horticulture during 1983-1985. Pure seeds of the two subspecies of Vigna unguiculata, viz. unguiculata and sesguipedalis were sown and crop raised. Direct and reciprocal crosses were made. Morphological and cytological investigations were done. It was found that the two subspecies easily crossable. In both the subspecies there was high prefertilisation shed. The chromosome number of subsp. unguiculata was 2n=22, of subsp. sesguipedalis 2n=24 and of F1 hybrid was 2n= 23. Both the parents and hybrid showed cells with laggards. Length of meiotic and somatic metaphase chromosomes was more in subsp. sesguipedalis, lowest in subsp. unguiculata and intermediate in their F1 hybrid. Both the subspecies and their hybrid had almost similar TF % which gave an indication of similarity in their karyotypes. Pollen fertility was more in subsp. sesguipedalis. Reciprocal difference was seen in the case of morphological characters like height of the plant, number of primary branches, internodal length, seeds per pod, seed colour and seed volume. However, these differences were not seen traceable in the cytology of the hybrid.