بررسی خصوصیات بیوشیمیایی و عملکرد دانه ژنوتیپ‌های منتخب جو وحشی (Hordeum vulgare ssp. spontaneum) در سطوح مختلف تنش خشکی

Drought is one of the most significant a biotic stresses that affecting plant&rsquo;s growth and development wild barley, H.spontaneum, the progenitor of cultivated barley has a high potential in terms of tolerance to environmental stresses. This research was performed on nine genotypes of Hordeum spontaneum, to study drought tolerance in a split plot experiment based on Randomized Complete Block Design with three replications under field shelter in 2011-2012. The main plot included three levels of water stress as normal irrigation, water withholding at flowering stage and no irrigation and sub-plots comprised the studied genotypes. The results indicated that the effect of drought stress on plant height, grain yield, biomass, relative water content, osmotic adjustment, stomatal conductivity, chlorophyll content, catalase, ascorbate peroxidase and peroxidase, protein, malondialdehyde, and proline was significant (P<0.01). The results of principal component analysis on the whole evaluated traits in drought stress condition located the studied genotypes in four groups. The first and second group comprised genotypes 6, 4 and 5. These genotypes had significantly higher grain yield, relative water content, chlorophyll content, enzymatic activity of peroxidase and ascorbate peroxidase and lower content of malondialdehyde, leaf temperature and osmotic potential (more negative) and therefore, were identified as tolerant genotypes.