Karyological analysis of bitter gourd (Momordica charantia L., Cucurbitaceae) from Southeast Asian countries

Abstract

Momordica charantia L. (Cucurbitaceae) is a commonly cultivated functional food plant. In the present study, karyological variation among 34 accessions of M. charantia originating from the Indian subcontinent (Bangladesh, India and Pakistan) and Thailand was evaluated. Ploidy levels ranging from diploid (2n= 22) to hexaploid (2n= 66) were observed. Hexaploidy in M. charantia is reported herein for the first time. Chromosome length ranged from 0.8 to 2.9 μm. The hexaploid accessions had submetacentric and subtelocentric chromosomes. All accessions harboured median and submedian chromosomes. Only one hexaploid accession (TOT1140) had chromosomes with subterminal centromeres. There was considerable variation in chromosome length and chromosome arm ratio.