Evaluation of the effects of flooding and drought environment on the emergence of gene regions controlling rice (Oryza sativa L.) seedling traits using SSR markers

Identification of genes related to stresses tolerance and mechanisms of tolerance is an important factor for developing tolerant plants. For this purpose, an experiment was conducted based on completely random design with three replications with 99 rice genotypes under flooding and drought stress at Gonbad Kavous University in 2018. To apply drought stress, irrigation was stopped at the three-leaf stage. According to the humidity curve, the stress level of 2% by weight moisture was estimated to be -0.55 MPa. Significant differences were detected between traits in both conditions. The result of association analysis of molecular and phenotype studies under flooding condition revealed that among the alleles, the RM129A allele with stem fresh weight and root length, the RM129G allele with root fresh weight and the width of the largest leaf, the RM129B allele with root dry weight and the length of the largest leaf, the RM1029I allele with stem dry weight and the length of the largest leaf, and under the drought condition, the RM1029G allele with stem dry weight, root volume, and the number of roots were maximally associated with the relevant traits under study. RM1029 was recognized as one of the most important primers at the seedling stage. The results of this research can be used to increase drought tolerance in rice varieties.