Investigation of Morphological, Yield and Yield Components of Aerobic and Lowland Rice Genotypes (Oryza sativa L.) Under Normal and Drought Stress Conditions

Considering to drought stress importance as most important limiting factor in rice production in world, identification of tolerant genotypes to drought can be a valuable approach to deal with the drought stress. In the present experiment plant materials contains 53 rice genotypes including 31 aerobic and 22 lowland (landrace) rice that were grown in two conditions under drought stress and normal as randomized complete block design with three replications in Sangar Rasht, Iran. The 18 plant characteristics including morphological traits, yield and yield components were measured. The results of ANOVA revealed for all traits differences among genotypes were significant at 0.01 probability level that showing high level diversity and different reaction of varieties among genotypes under two conditions. The cluster analysis assigned all genotypes in three groups in each condition. In normal condition second group with 21 memberships including 14 aerobic genotypes and 7 lowland genotypes gained average of yield traits such as grain yield, weight of total plant panicle, weight of main stem panicle, number of total grain, number of filled grains higher than other genotypes. Under drought stress condition the most desirable genotypes belonged to the second group. This group contains 19 aerobic genotypes and 4 lowland genotypes in term of traits related to yield including weight of total plant panicle, weight of main stem panicle, grain yield, dry weight of plant, 1000 grain weight, number of total grain and number of filled were better than other genotypes. Totally 11 aerobic genotypes and 2 lowland genotypes (Dorfak and Gohar) were in better group in term of grain yield and yield components.