CYTOMORPHOLOGICAL STUDIES IN VIGNA

Detailed cytomorphological studies have made in Vigna grahamianus Verdc. and V. wightii Benth. Of the three cultivars of V. luteola from Brazil, South Africa and Australia, the Australian cultivar shows better performance in our botanic garden as a higher yielding type. Cytological studies have also been made in this cultivar. In all the three species, the somatic chromosome number is 2n = 22 and as far as we are aware, the first record of chromosome number has been made in V. grahamianus and V. wightii. In V. grahamianus there are frequent occurrences of amitotic divisors and anaphasic bridges and laggards, but the fertility of the plant has been affected in this species. All the three species studies are distinct in having different karyotypes of chromosomes and deviant absolute chromosome lengths. The Australian cultivar of V. luteola is diploid and the present study confirms the earlier determination in somatic chromosome number.