Inheritance of seed germination related traits for drought tolerance in bread wheat cultivars

To determine the inheritance of germination related traits in bread wheat, a 8×8 diallel cross design was carried out in 2007 at the Ardebil Branch, Islamic Azad University, Iran. The F1 and F2 seeds were germinated under osmotic stress and also subjected to atmospheric drought stress. Different germination rate indices, seedling characteristics and germination recovery after desiccation were measured and recorded. For evaluating the relationship between germination characteristics and drought tolerance, 18 wheat varieties including the parents of diallel cross were grown under irrigated and rainfed conditions in the field. Results of these experiments indicated that germination rate indices had high narrow sense heritability and close relationship with drought tolerance. Among seedling characteristics, coleoptile length under normal condition showed high narrow sense heritability and a close relationship with drought tolerance. Root number under stress conditions was considered as a moderately heritable character with significant relationship with drought tolerance indices. Despite of the close relationship of root: shoot length ratio with drought tolerance, it had low narrow sense heritability. Germination recovery showed negative relationship with drought tolerance and had low narrow sense heritability.