EFFECT OF COLCHICINE TREATMENT ON SEED SPROUTING AND PHENOTYPE OF SOME COWPEA AND VIGNA VEXILLATA ACCESSIONS

Abstract

Fifteen accessions of two species of Vigna which comprise ten lines of cultivated cowpea, (V. ungniculate (L) Walp) and five lines of its wild relative (V. vexillata (L) A. Richard) were subjected to colchicine treatment for polyloidization. The plants were treated with 0.1%, 0.2% and 0.4% colchicine and were monitored for their seed sprouting and phenotropic responses by comparing them with their respective control plants. Putative colchiploids that showed persistent polypoid traits under 0.2% and  0.4% colchicine were obtained in five accessions comprising two accessions of V.unguiculata and three accessions of V.Vexillata. Quantitative and qualitative differences in the vegetative and reproductive characters were observed between the putative colchiploids and their respective control plants. Colchicine concentrations ranging between 0.2% and 0.4% are suggested to be adequate for induction of polyploidy in Vigna species.