Source-Sink Relationsionship Studies in Multicapsule Genotypes of Sesame

Abstract

A study was conducted to determine the source and sink relationship in multicapsule genotypes of sesame.  Thirty-six multicapsule genotypes along with two single capsule genotypes as checks were used in this study. Data on source characters such as number of leaf axils, leaf area, SPAD chlorophyll, photosynthetic rate, plant height, stem girth was recorded at capsule formation stage. Similarly, data on sink related characters such as number of flowers per axil, number of capsules per axil, capsule length, breadth, seed weight, seed yield per plant, and oil content were recorded.  There were 1 to 3 capsules per axil, genotypes, SC-500-1, PI-154298, JCS-1020, exhibited 3 capsules at every axil.  The results indicated the source characters such as number of leaf axils per plant was significantly positively correlated with seed yield per plant, leaf area was significantly positively correlated with number of flowers per main stem, total capsule number per main stem and seed weight of the right capsule in the bunch of the capsules. SPAD chlorophyll was positively associated with, number of flowers per axil, number of capsules per axil and seed yield per plant. Photosynthetic rate was significantly associated with total number of capsules per main stem of the plant, oil content and test weight. There were 7 principal components which explained 80 of the variation presents in the genotypes. Characters such as number of flowers per axil, number of leaf axils per plant, number of capsules per axil in the main stem and capsule length, weight, seed weight of left and right capsules contributed for the variation. Variation in these characters distributed the genotypes across the axis in the PCA biplot. Genotypes such as SC-500, PI-154298 exhibited high capsules number per plant, capsules per axil, capsule length and capsule seed weight. This study indicated that the genotypes showing more than 1 capsules per axil have high leaf area, stem girth. These genotypes are potential source for utilization in yield improvement programmes.