KARYOTYPIC ANALYSIS IN MUNGBEAN (VIGNA-RADIATA (L) WILCZEK)

Karyotypic analysis in 10 morphologically diverse varieties of mungbea n showed that all the varieties were diploid having 22 chromosomes in their somatic cells and their haploid number was 11. While individual chromosome length ranged from 1.20 to 2.35 mm, the total length of hap loid set varied from 18.30 to 22.33 mm. Of the eleven basic chromosome s, two were found to have a secondary constriction with subterminal pr imary constriction and these fell in either long or in medium chromoso me group. In respect of centromere position all the varieties had six metacentric and five submetacentric chromosomes, where the centromeric formula 5 sm + 6 m could be assigned. Detailed karyotypic characteris tics differed slightly among the varieties. TF% varied from 40.04 to 4 1.45 indicating a high degree of karyotypic similarity among the varie ties. All the varieties except Q10593 had 2A type of karyotype. On the other hand, Q10593 fell in 2B group. The low magnitude of difference in chromosome characteristics of the morphologically diverse varieties indicated that genetic processes such as mutation rather than chromos omal changes have played an important role in the intraspecific evolut ion of mungbean.