SELECTION OF HIGH YIELDING LINES FROM HETEROGENEOUS JORDANIAN BARLEY LANDRACES UNDER WELL WATERED AND DROUGHT STRESS CONDITIONS

Abstract

Nine agronomic traits were recorded on one hundred and sixty five barley lines under well watered and drought stress conditions. The objectives were to estimate the heritability and expected genetic advance from selection for yield, yield components, plant height and phenological traits and to examine the interrelationships among these traits. Results showed a significant (P<0.01) reduction in yield and growth under drought compared to well-watered conditions. Higher estimates of heritability and phenotypic/genotypic variances were observed under well watered than under drought conditions, which might indicate that direct selection under well watered conditions is more efficient to improve yield and/or plant biomass than indirect selection under drought. Higher heritability values were found to be associated with high predicted genetic advance from selection for grain yield, biological yield and yield components in well watered environment, indicating that heritability of these characters is most likely due to additive gene effects. Positive associations were found between grain yield and yield components combined with high magnitude of heritability and genetic advance, indicating that direct selection for yield per se or indirect selection for yield components would be effective to improve plant biomass. First three principle components explained more than 60% of total genetic variation with high loading from grain yield and yield components, indicating that these traits account for a maximal amount of total variance present among studied barley lines. In conclusion, our results showed that heterogeneous barley populations are a valuable source to expand genetic variability in barley and to select high performing lines.