Identification of traits related to drought tolerance in barley (Hordeum vulgare L) genotypes originated from arid climates of Iran

To evaluate the effects of water deficit stress in barley germplasm collection of National Gene Bank of Iran، 25 genotypes collected from arid and semi arid provinces of Iran and 3 sample cultivars were studied in two environments including: non-stressed and water deficit stress. Agronomical، phenological and morphological traits were measured. Stress indices were calculated to determine tolerant genotypes. Based on correlation coeficiences، STI were better indicator of drought stress tolerance than the other indices. Based on STI، morphotypes number 16، 24، 25 and 26 shown better stress tolerance potential than the other morphotypes. Stepwise regression between stress tolerance index (STI) and quantitave traits indicates the important role of leaf area and specific leaf area of flag leaf under drought stress condition، in acclimation to drought conditions. It is also concluded that the 100 grain weight is the only trait under normal condition witch shows a close relation with stress tolerance index.