Genetic analysis of ajowan (Trachyspermum ammi L.)

A field experiment was conducted to study the growth and yield performance of ajowan genotypes (Trachyspermum ammi L.) at the Department of Spices and Plantation Crops, Horticultural College and Research Institute, TNAU, Periyakulam during 2012-2013. In total twenty genotypes of ajowan collected from different parts of India were evaluated under field conditions. The experiment was laid out in a randomized block design (RBD) with three replications. Higher phenotypic and genotypic variation was recorded by the traits: number of flowers umbel^-1, number of umbels plant^-1, number of seeds umbel^-1. Phenotypic and genotypic coefficients of variation were found to be high for seed yield plant^-1. The lowest genotypic coefficient of variation (GCV) was observed for the plant height, days taken for first flowering, days taken for 50% flowering, number of primary branches plant^-1, number of flowers umbellet^-1, percentage of fruit set, number of seeds umbellet^-1, 1000 seed weight. The lowest phenotypic coefficient of variation (PCV) was recorded by days taken for first flowering, days taken for 50% flowering, number of flowers umbellet^-1 and 1000 seed weight. High heritability coupled with high genetic advance was recorded by 1000 seed weight, seed yield plant^-1, seed yield ha^-1, number of umbels plant^-1, number of flowers umbel^-1, number of umbellets umbel^-1, number of secondary branches plant^-1, percentage of fruit set, plant height and days taken for 50% flowering. Correlation study showed that there is a positive correlation between the traits number of umbellets umbel^-1, number of flowers umbel^-1, number of seeds umbel^-1 and seed yield plant^-1 at both genotypic and phenotypic levels. The path analysis enlightened that the traits seed yield plant^-1, number of secondary branches plant^-1, number of seeds umbellet^-1 and percentage of fruit set had positive direct effect on the seed yield ha^-1, suggesting that such traits could be selected in further breeding programmes. Among the genotypes evaluated, the genotypes Acc. No.3, LTa-26, LS-1 and GA-1 recorded higher seed yield plant^-1.