ارزﻳﺎﺑﻲ ﺗﺤﻤﻞ ﺑﻪ ﺗﻨﺶ ﺧﺸﻜﻲ ژﻧﻮﺗﻴﭗﻫﺎی ﺳﻮرﮔﻮم ﻋﻠﻮﻓﻪای( Sorghum Bicolor (L) Moench) در ﻣﺮﺣﻠﻪ رﺷﺪ روﻳﺸﻲ

In order to understand the effects of drought on forage yield of forage sorghum pure lines(Sorghum bicolor (L) Moench) an experiment was conducted on Torogh agriculture research center at 2010. The 64 genotypes of forage sorghum selected from sorghum breeding program in Mashhad. A simple lattice design (8×8) with tow replications was used to evaluate the fresh and dry mater yield as two important traits. The results showed that variance analysis of total fresh and dry fodder yield in 64 varieties in first and second harvest at normal and stress condition were significantly difference at 1% probability levels. Stress tolerance index (STI), geometric mean productivity (GMP) and mean productivity (MP) had positive and significant correlation with fodder yield in normal and drought conditions. Assessment of genotypes biased on drought indices showed that 1, 20 and 36 genotypes determined as the drought tolerance pure lines respectively . Also, stress tolerance index (STI), geometric mean productivity (GMP) and mean productivity (MP) indexes were determined as most appropriate indicators in evaluation of drought tolerance in forage sorghum genotypes.