اثرتنش گرما و شوری بر جوانه زنی، رشد گیاهچه در ژنوتیپ های آفتابگردان

This study was conducted to evaluate the effect of salinity and high temperature stress on germination and seedling growth of sunflower genotypes. The experimental factors consisted of temperature regimes (25/15 and 35/20ºC day/night), salinity (distill water, 2, 4, 6, 8 and 12 Ds/m) and sunflower genotypes (Azargool, Faroukh and Ghasemi). Experiment was in the form of factorial with completely randomized design and three replicates. Results indicated that the radicle, plumule and seedling length and also, germination percentage and rate effected significantly by genotypes, temperature regimes and their interaction (P<1%). The highest seedling growth in sunflower genotypes was occurred in 25/15 ºC treatment. Otherwise the highest germination rate was in higher temperatures (35/20ºC day/night). Ghosimi hybrid had higher susceptibility to salinity and heat stress. Higher temperatures increased the negative impacts of salinity on germination and seedling growth on sunflower genotypes.