Genetic variability and association among yield, yield related traits and oil content in Ethiopian garden cress (Lepidium sativum L.) genotypes

Garden cress (Lepidium sativum L.) is one of the aromatic plant species of Ethiopia containing edible oil with several medicinal implications. Grain yield and oil content of garden cress are usually low, depending on genetic variability and other important characters with these traits. Hence, the objectives of this study were to investigate genetic variability and association among characters. Forty nine garden cress genotypes were tested using randomized complete block design at Debre Zeit Agricultural Research Center, Ethiopia during the main cropping season of 2011. The analysis of variance showed highly significant (p≤0.01) difference among the studied genotypes for all characters, except for fatty oil content, indicating the existence of variability and the potential for selection and improvement within characters. High phenotypic and genotypic variation was recorded for harvest index, seed yield per plant, biomass yield per plant and biomass yield per plot. Seed yield per plot had the highest heritability value. Path coefficient analysis at both phenotypic and genotypic levels showed that number of seeds per plant, days to flowering initiation, biomass yield per plant, harvest index and 1000 seed weight had strong direct effect on seed yield. This indicates that breeding programs should be based on these traits for further improvement of the crop.   Key words: Correlation coefficient, genetic advance, genetic divergence, heritability, medicinal plant, path coefficient