بررسی تأثیر تنش خشکی بر عملکرد و اجزای عملکرد ژنوتیپ های گلرنگ بهاره

To investigate the effects of water deficit stress on yield and yield components of safflower genotypes , an experiment was performed based on split plot in a randomized complete block design with three replications at the research farm of the Islamic Azad University, Branch Khorasgan in 2012 . Irrigation treatments consisted of two levels (75 and 125 mm evaporation from pan class A) as a main plot and 20 genotypes as a sub plot. Number of seed per head was reduced under drought stress condition, and the highest amount of number of seeds per head was observed in Kurdistan and the lowest in Palestine genotype. Genotypes Syria, Hamadan and Ac-sunset revealed higher yield in contrast to other genotypes under stress environment that is related to their adaptability to stress condition. On the other hand, high level of biological yield was obtained in Kurdistan in comparison to other cultivars. Therefor these genotype had higher tolerance to drought stress. Significant difference for harvest index in Shiraz and Ac-sunset genotypes with other cultivars was caused higher drought tolerance and increasing of photosynthetic dry water mobilization to grain.