تاثيرتنش شوري (كلريد سديم ) بر رشد و تثبيت بيولوژيك نيتروژن در بازده رقم سويا

Symbiotic nitrogen fixation in soybean cultivars (Glycine max L.)

The purpose of this study was to investigate the effect of salt stress on growth and symbiotic nitrogen fixation in soybean cultivars (Glycine max. L). These cultivars were planted 6 July 2001 in a randomized complete blocks design with three replicates and two factors. The factors included different cultivars (11 cultivars) and salinity levels (0,30,60,80) Mm/L. The plants were grown in sand culture and were irrigated with a Hoagland nutrient solution without nitrogen containing 0,30,60 and 80 Mm/L NaCl under greenhouse conditions. Seedlings were harvested after 60 days and leaf area, nodule number, dry wight for steam, leaf, root and nodule, nitrogen percentage and nitrogen yield were measured. Results showed that with invreasing salinity, all traits decrease. Mean comparsion showed that cultivars Dear and Gorgan3 are better then other cultivars with respect to nodule number, leaf area, dry weights, nitrogen percentage and nitrogen yield. Cultivars L.W.K and B.P were the worst. Calculation of sensitivity index showed that Dear, Hill and Gorgan3 have the highest and L.W.K and Williams have the lowest tolerance to salinity. It seems that cultivars Dear and Gorgan3 (with highest dry matter production) and Dear and Hill (with lowest sensitivity index) are promised for breeding efforts.