In situ 4C DNA content study of twenty-nine hybrid varieties of some selected taxa of tribe phaseolae (Fabaceae)

A quantitative study of in situ estimation of 4C nuclear DNA amount and chromosome counts were carried out on different genera, species and varieties of economically important legumes (twenty nine hybrid varieties of Glycine max, Erythrina variegata, Lablab purpureus, Vigna unguiculata, Canavalia ensiformis, Canavalia gladiata and Cajanuscajan) of the tribe Phaseolae (family Fabaceae). The 4C nuclear DNA amount was estimated through in situ Feulgen micro spectrophotometry expressed in arbitrary units of relative absorbance. Somatic chromosome number is studied which is constant at intra-specific level, but not at inter-specific level. There were significant variations in 4C DNA amount at the inter-specific but not at the intra-specific level. To considering nuclear DNA amount in relation to total chromosome length, the diversity in DNA amount was also associated with structural differences of chromosomes among the different species. The variation in 4C DNA content was non significant at the varietal level, though in most of the cases the variations were significant at species and generic level.