Study of Root Growth, Biological Yield and Grain Yield of Wheat Genotypes Under Waterlogging Stress During Different Growth Stages

In order to study the effects of different waterlogging duration in growth stages ZGS11, ZGS13 and ZGS31 on root and shoot growth of three wheat genotypes Chamran, Vee/Nac and Yavaros, a pot experiment was carried out in the Ramin Agricultural and Natural Resources University in 2004. The experiment was a factorial according to a Randomized Complete Block Design with three replications. Study of root dry weight and root elongation trend showed different responses among genotypes, start of waterlogging periods and different waterlogging levels, as short period of waterlogging (10 days), had unrecoverable effects on the growth. Analysis of variance of root dry weight and root length at the anthesis and physiological maturity stages indicated significant different among all of treatments levels. Vee/Nac genotype was found superior with respect of root dry weight and root length to other genotypes. ZGS11 and ZGS31, had the highest and the lowest responses to waterlogging, respectively. Duration of 10, 20 and 30 days waterlogging at anthesis stage decreased 37.75, 44.31 and 54.01% of root dry weight, and 25.85, 47.02 and 58.88% of root length compared to control, respectively. Investigation of the root anatomy of wheat genotypes under waterlogging stress showed formation of cortical root aerenchyma as a waterlogging-resistantce mechanism.