Study and systemic analysis on yield and yield components association for sesame (sesamum indicum l.) Breeding

High status of sesame (Sesamum indicum L.) among oil-seed crops, requires identification of relationship between yield components and yield potential. The information are important for its yield improvement. This study was carried out on 32 multi-branched sesame genotypes. Positive and significant correlations were detected between number of capsules per plant, number of seeds per capsule, length of main inflorescence and 1000-seeds weight. However, distance of the first branch and first capsule from soil surface showed significant and negative correlation with seed yield. Based on stepwise regression and consequently ordinary path analysis, number of capsules per plant, number of seeds per capsule, length of main inflorescence, and 1000- seeds weight had the highest direct effects on yield formation, respectively. Comparing with ordinary path analysis, sequential path analysis showed higher values for direct effects of main inflorescence length, number of capsules per plant, and 1000-seeds weight, and indirect effect of number of branches per plant and main inflorescence length through number of capsule per plant. Factor analysis showed three factors explained about 80% of total data variations. First factor compared number of capsules per plant, length of main inflorescence versus distance of first capsule and first branch from soil surface. The second factor had positive effects on capsule length, number of seeds per capsule, and 1000-seeds weight. Third factor had positive effects on number of capsules per plant and number of branches per plant. These results are similar to correlation analysis results. Based on path analysis and specificity of factors, selection for lower distance of first capsule and first branch from soil surface (which could be done in early fruit set stages) has the same results as the selection for higher number of capsules per plant and main inflorescence length toward yield improvement. The results of selection based on higher number of seeds per capsule and 1000-seeds weight (which have less direct effects on seed yield) could be achieved by selection based on longer capsule length. The latter traits could be measured non-destructively. The nature of third factor indicated selection based on number of branches per plant might result in an improvement in seed yield.