Evaluation of Genetic Diversity in Bitter Vetch Based on Morphological and Agronomic Traits under Normal and Water Deficit Stress Conditions

Background and Aim: Bitter vetch is an ancient legume crop grown for forage and grain. The crop has the ability of soil nitrogen fixation and can be grown in shallow and alkaline soils. To study genetic diversity, morphological and agronomic traits of ۱۶ bitter vetch genotypes were evaluated in randomized complete block designs with three replications under two normal and water deficit conditions at research farm of Razi University during ۲۰۱۵-۲۰۱۶ crop season. Genetic parameters including genetic variance, phenotypic variance, environmental variance, phenotypic coefficient of variation, genetic coefficient of variation, environmental coefficient of variation, broadsense heritability, co-heritability and genetic gain were estimated for all the traits.Combined analysis of variance showed significant effect of the environment on most of the traits. As a whole, the number of seeds per plant had the highest phenotypic coefficient of variation. Under normal conditions, genetic correlations between grain yield and grain filling period, number of branches, number of pods per plant, number of seeds per plant, ۱۰۰۰-grain weight, biological yield, and harvest index were positive and significant. In water deficit stress conditions, grain yield was positively correlated with grain filling period, plant height, number of seeds per plant, number of pods per plant, number of seeds per plant, ۱۰۰۰-grain weight, biological yield and harvest index. As a whole, phenotypic correlations were higher than genetic correlations, indicating the significant effect of environment on the genotypes performance. The value of yield heritability in combination with the other traits was higher than heritability of yield itself, indicating the potential for improving yield by selection through the traits.Methods: To study genetic diversity, morphological and agronomic traits of ۱۶ bitter vetch genotypes were evaluated in randomized complete block designs with three replications under two normal and water deficit conditions at research farm of Razi University during ۲۰۱۵-۲۰۱۶ crop season. Genetic parameters including genetic variance, phenotypic variance, environmental variance, phenotypic coefficient of variation, genetic coefficient of variation, environmental coefficient of variation, broadsense heritability, co-heritability and genetic gain were estimated for all the traits.Results: Combined analysis of variance showed significant effect of the environment on most of the traits. As a whole, the number of seeds per plant had the highest phenotypic coefficient of variation. Under normal conditions, genetic correlations between grain yield and grain filling period, number of branches, number of pods per plant, number of seeds per plant, ۱۰۰۰-grain weight, biological yield, and harvest index were positive and significant. In water deficit stress conditions, grain yield was positively correlated with grain filling period, plant height, number of seeds per plant, number of pods per plant, number of seeds per plant, ۱۰۰۰-grain weight, biological yield and harvest index.Conclusion: As a whole, phenotypic correlations were higher than genetic correlations, indicating the significant effect of environment on the genotypes performance. The value of yield heritability in combination with the other traits was higher than heritability of yield itself, indicating the potential for improving yield by selection through the traits.

Keywords:

Bitter vetch , Correlation , Genetic parameters , Water deficit stress.