Genetic diversity for morphological traits of rice genotypes under cold stress

In order to investigate diversity between some rice genotypes in cold stress condition, 2 genotypes including 11 native genotypes and 11 foreign genotypes were evaluated. Experiment was carried out as split plot based on a completely randomized design with three replications. The genotypes were evaluated in normal and cold stress (10° C) conditions in an incubator. For evaluating phenotypic variation in rice genotypes, root length, shoot length and root and shoot weight were measured. Result showed the significant differences of the studied traits in cold stress condition. Besides, interaction effect of genotype and cold stress condition was significant for all the studied traits. Correlation coefficients between seedlings traits in normal and stress conditions and sensitivity and tolerance indices were high and significant. Cluster analysis based on seedling traits in cold stress condition grouped the genotypes into three groups that susceptible and tolerant genotype were separated from each other. Cluster analysis based on stress tolerant indices for morphological characteristics also separated sensitive and tolerant genotypes from each other. Significant differences between genotypes demonstrated genetic variation for evaluated traits at seedling stage of rice in cold stress condition.