Abstract:
A study was undertaken in the Department of Agricultural Botany, College of Horticulture, Vellanikkara during October 1992 to February, 1993 to assess the variability existing in a population of 50 genotypes of horse gram. Evaluations based on the physiological parameters were also carried out.
The results revealed the presence of sufficient genetic variability in the different genotypes studied, which were of different geographical origin. High heritability and genetic advance exhibited by the characters, length of pods and number of pods per plant point towards the possibility of these traits to be improved by direct selection. Environmental effect was found to be comparatively higher for yield and number of seeds per pod.
Correlation studies indicated maximum correlation of yield with number of seeds per pod and number of pods per plant. Association studies among the different traits showed positive significant correlations between the character pairs, plant height and length of pods, number of primary branches and number of pods per plant, days to 50 per cent flowering and days to maturity; length of pods and number of seeds per pod and 100 seed weight and days to maturity.
Divergence analysis gave eleven clusters of which, cluster II and VI showed maximum distance of the cluster members from cluster centroids. The members of these two clusters could be considered superior as parents, for hybridization programme. The maximum mean value for yield was exhibited by members of cluster II. The maximum contribution towards genetic divergence was made by the character 100 seed weight.
Growth analysis based as physiological parameters like dry matter production, NAR, CGR, LAI and HI suggested that an ideal plant type will be one in which maximum dry matter production, net assimilation rate and leaf area index was observed during the middle growth stage. An efficient partitioning of dry matter towards the reproductive parts was also an essential criterian.
