Evaluation of the Response of Bread Wheat Genotypes to Supplementary Irrigation with Respect to Grain Yield and some Agronomical and Physiological Traits

In order to study the effect of supplementary irrigation on grain yield of 20 advanced bread wheat lines from population of recombinant inbred lines, selected from Azar2/87Zhong291, this experiment was conducted using randomized block design with three replications under supplementary irrigation during 2008-09 seasons at the Dryland Agricultural Research Institute (DARI) of Maragheh. Characters under study were: days to heading, plant height, days to maturity, 1000 kernel weight, tiller number, spike length, seed number per spike, spikelet number per spike, peduncle length, leaf sheath length, grain and biologic yields. Analysis of variance revealed significant differences among genotypes with respect to the most of the traits studied. Results showed that the lines No. 4 and 16 with 3400 and 3680 kg/ha grain yield were significantly superior under supplementary irrigation conditions. Based on the results the traits such as leaf sheath length, seed number and spike weight, tiller number and HI showed positive and significant correlation with grain yield. Path analysis indicated that leaf sheath length, seed number per spike and 1000 kernel weight were important traits to select lines for high yield potential under supplementary irrigation condition, but days to maturity showed negative effect on grain yield. As a whole, the line no. 16 (Azar2/78Zhong291-53) with high yield (3680 kg/ha) under supplementary irrigation, early maturity, 1000 kernel weight and HI, can be selected as a suitable genotype.