Evaluation of Genetic Parameters of Important Agronomic Traits of Sesame in Irrigated and Water-Limited Conditions using Diallel Cross Method

In this study, half diallel cross method with Grifing method II and model mixed B was used to evaluate genetic parameters for physiological and morphological traits in seven lines of sesame and their 21 F2 populations under normal irrigation and water limited (water withholding before flowering) conditions. Mean of evaluated GCA/SCA under normal irrigation indicated that days to flowering, days to end of flowering, flowering duration, days to maturity, number of capsule per main stem, 1000-seed weight, main stem yield, capsule length, internode lengh, number of infertile nodes, number of capsule bearing nodes, and total number of nodes were mostly controlled by additive gene effects, some by non-additive gene effects and in some cases by a balance between the two genes mode of actions. Heritability in the broad sence varied from 58.4% for internode length to 97.7% for number of capsule per plant. Narrow sense heritability was high for number of capsule per plant (82.5%) and days to maturity (80.5%), indicated high selection efficiency for these traits under water limited condition. All the evaluated traits were governed by additive effects which indicated a shift in genetic control of the traits compared to normal irrigated condition. Broad sense heritability appeared to be unchanged but evaluation of narrow sense heritability was lower in water limited condition compared to normal irrigated, which may indicate reduction in breeding progress rate.