ارزيابي تحمل به خشكي ارقام و لاين هاي جو به تنش خشكي انتهاي فصل رشد

Evaluation of Drought Tolerance of Barley {Hordeum vulgare L.) Cultivars and Lines to Late Season Drought

To measure the effects of late season drought stress on agronomic traits of 20 barley genotypes, two different experiments in completely randomized block designs with three replications, one under drought stress and other non-stress conditions, were conducted at Mashhad during 2007- 2008 growing season. The purpose of this study was to find genotypes tolerant to stress and non-stress conditions. The results showed significant difference among genotypes for grain yield, number of spike per m2, grains per spikel, 1000 grain weight, grain filling period, plant height, biological yield, harvest index for both under stress and non stress conditions. Drought stress caused significant reduction on whole agronomic traits. The highest average grain yield under two experimental conditions belonged to the genotypes No .20 (6478 kghʹ1) and 8 (5393 kghʹ1). While the lowest grain yield produced of the genotypes Nos.14 and 4, with 2250 and 2661 kg/ha respectively. The highest correlation of grain yield under stress condition was attributed to 1000 grain weight (r = 0.55 **) and non stress condition to harvest index (r = 0.66**) .The results indicated that three indices of MP , GMP and STI had highest positive and significant correlation with yield at both conditions . Comparison of their values (STI, GMP, and MP) showed that genotype No.20 (M-82-14) to be highest producer at both conditions. It can thus be recommended to drought stress condition. This genotype is promising line in temperate region of Iran with highest grain yield (7729 kghʹ1) and (5245 kghʹ1) at non stress and stress conditions respectively. The genotypes No. 8 (D5) and No 18 (M-80 -16) were the other suitable genotypes. Based on these indices genotype No 4 (fassih) was un- suitable to drought condition. Its MP, GMP and STI, values were 2661, 1920 and 0.11 respectively.