Effects of moisture limitation on yield and dry matter distribution between shoot and root of triticale (Triticosecale ×Wittmack) genotypes under controlled conditions

A study was conducted to evaluate the effects of moisture limitation on yield and dry matter distribution between shoot and root of triticale genotypes. This study was performed using a factorial experiment based on completely randomized design with four replications, in Agricultural College of Ferdowsi University of Mashhad greenhouse during 2009. Treatments were two available soil water including irrigated after 50% and 75% depletion of moisture from root zoning (as a check and moisture limitation, respectively) and four triticale genotypes (ET-82-8, ET- 82-15, Et- 79-17 and Juanillo-92). Results showed that the significant (P>0.01) decrease in grain yield due the drought stress about 32 percent, but the effects of genotypes and interaction of moisture limitation and genotypes were not significant. Total above ground dry weight, leaf plus shoot and spikelet dry weight decreased with drought moisture limitation. Moisture limitation had significant (P> 0.01) decrease in root depth about 16 percent. Also genotypes and treatment's interactions had significant effects on root depth (P>0.05). Moisture limitation and genotypes showed significant effects (P>0.01) but interactions were not significant. About 46 percent decrease on root dry weight was due from moisture limitation. Experimental treatments and their interactions had significant effects on total root area. Genotypes and interactions were significant effects (P>0.01) on root/shoot ratio, but the effect of moisture limitation was not significant. Finally, results showed that while the ET-82-8had the better growth characters, its drought susceptibility index (DSI) was lower which indicate the lower susceptibility and high yield stability of this genotype under stress conditions.