Determination of chromosomes controlling physiological traits associated to drought tolerance in rye

Drought stress as the most important abiotic stress plays an important role in yield reduction of crop plant worldwide. Considering physiological indices to improve drought resistance, is of major importance.In order to evaluate Chromosomal Locations of physiological indices for drought tolerance in wild species of rye a complete series of disomic addition lines of rye, donor parents (Secale cereale L.cv. Imperial) and recipient (Triticum aestivum L.cv. Chinese Spring) were studied under field, greenhouse and laboratory conditions in College of Agriculture at Razi University in 1998. Disomic addition lines showed significant differences for relative water content (RWC), relative water loss (RWL), water use efficiency (WUE), and stomatal resistance (SR), implying genetic variation and possibility of selection for improving drought tolerance in disomic addition lines. Physiological indices of stomatal resistance, relative water loss and water use efficiency played an important role in determination of regression equation of grain yield under stress condition. Based on the physiological multiple selection index (MSI), it is interperated that quantitative traits loci (QTLs) controlling physiological characteristics for drought tolerance in rye are most likely located on chromosomes 3R and 7R. Assessment of disomic addition lines based on stress tolerance index (STI) and germination stress index (GSI) also indicated that QTLs controlling drought tolerance in rye are associated to chromosomes 3R and 7R.