Document Type : Research Paper
1 Plant Breeding and Biotechnology Department, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Gonbad Kavous University, Iran
To evaluation of the genetic structure of drought tolerance in rice, an experiment was conducted using 120 RILs in a randomized complete block design with three replications in Gonbad Kavous University. 16 and 20 QTLs were identified at vegetative and reproductive stages, respectively. The correlation variance analysis results indicated a significant relationship between traits under normal and drought stress conditions at the two growth stages. At the vegetative stage, this significant difference was recorded in all studies traits, except for plant height, at the 1% level, suggesting the diversity of the analyzed lines for the measured traits. In a comparison of the three evaluated treatments, the qRN-12, qRS-11, and qRV-12 lines were determined as stable QTLs appropriate for a selection of drought-tolerant and drought-sensitive lines at the vegetative stage in different conditions. At the reproductive stage, the highest correlation coefficient was obtained in the panicle length from the comparison of traits in flooded and drought stress conditions. Several new alleles of drought-tolerant QTLs identified in this study. In two environmental conditions, the important detected QTLs, such as qNTF-12 and qNL-3, belonged to the numbers of fertile tillers and leaves, determined as stable QTLs at the reproductive stage. Most of the traits were identified on the rice chromosome 12 and its genomic regions. In this study, the QTLs identified at vegetative and reproductive stages can be used as stable and major QTLs for the selection of drought-tolerant and drought-sensitive lines at all plant growth stages using marker-assisted selection in the rice.