بررسي نقش همزيستي ميكوريزايي در افزايش مقاومت به خشكي دو رقم سورگوم دانه ايي

Effect of mycorrhizal symbiosis on increasing of drought resistance of two grain sorghum

To examine the effect of mycorrhizal symbiosis in increasing drought resistance in two genotypes of grain sorghum the study was carried out split factorial in complete randomized blokes whit three replicates in 1385 at research site of Azad University Faculty of Agriculture in Mahdasht, Karaj. Hydric stress was the main factor. Sorghum genotypes and mycorrhiza were the two secondary factors. Hydric stress measured as the evaporation levels of water (evaporation) basin at: (7/) 50 mm, (T2) 100 mm, and (:T3) 150 mm. Sorghum genotypes were: (V1) K.G.S.W.17 (Karaj Grain Sorghum White 17) and (V2) K.G.S.O.36 (Karaj Grain Sorghum Orange 36). Mycorrhiza was factored in as (m0) for no application of mycorrhiza and (m1) for application of mycorrhiza. Hydric stress was introduced when plants reached a height of about 50 cm. The result of the study showed that increased hydric stress effect in reduction 1000- seed weight and number of clusters in area (at statistically significance level of 1%), as well as the colonization of root system and grain yield (at statistically significance level of 5%).Applying mycorrhiza resulted in significant increases in, 1000-grain weight,, grain yield and number of clusters in area (p < 0.01). Applying genotype factor resulted in significant increases in grain yield, number of clusters in area, 1000-grain weight (p < 0.01).The result of this study showed that hydric stress had decreasing effect on the level of yield and yield component of two grain sorghum genotypes and the application of mycorrhiza can compensate for a part of the reduced yield.