ABSTRACT

The study reports the results of analysis of chromosomes of Vigna

siihterranea performed in the mitotic prometaphase and metaphase stages using

conventional techniques. The somatic chromosome study was done using the

shoot meristem as the root tips persistently showed ver'' low mitotic indices. The

result revealed somatic chromosome number of 2n 22. There was no evidence of

polyploidy in any of' the four (4) accessions. The chromoSome morphology was

described on the basis of the centromere position. From the F.% value, it was

evident that the different accessions showed wide range of variation in their

kaiyotypes. The F. % range of 33.33 to 50.00 was recorded for Ac-Ol. Ac-02 and

Ac-03. They had nietacentric and subinetacentric chromosomes while Ac-04 had

F.% range of 25.00 to 50.00. With the exception of the 91h chromosome pair that

was telocentric. the chromosomes were mostly metacentric and subrnetacentric.

The correlation studies between the arm lengths and the chromosome length

showed positive and significant relationship a)art from AC-02. where the

relationship between the short arm and the chromosome length was non-

significant. Since the accessions were diploid. the uniformity in chromosome

number of the four accessions investigated is a clear indication that they may have

evolved from a common ancestor, forming a homogeneous assemblage.