Identification of Quantitative Trait Loci Related to Germination Characterize in (Oryza sativa L.) Iranian Recombinant Inbred Lines of Rice under Different Osmotic Stresses

Osmotic stress (such as drought stress) is a serious limiting factor to rice production and yield stability in worldwide. In order to locate the QTL associated with tolerance to osmotic stresses in germination stage and determine the contribution of each QTL on the phenotypic variation caused 96 lines of F8 Anbarboo × Sepeedrud (tolerant and sensitive to drought stress in germination stage, respectively) an experiment was conducted at Gonbad Kavous university in 2011-2013. For construction of genetic linkage map, 365 SSR marker and 32 primer combination were evaluated. 136 polymorphic SSR markers and 21 primer combination were used for providing of linkage map. Germination components including root length, shoot, coleoptile and the percentage of seed germination was recorded for 100 seed of each line in the osmotic stress resulting from sucrose, sorbitol and mannitol. For root length in all three stress conditions was found a QTL on chromosome 4 that had positive effect in all cases. Among the identified QTL, qSUC-5 (QTL for coleoptile length under sucrose stress) on chromosome 5, qSUR-2 (QTL for radicle length under sucrose stress) on chromosome 2 and qSUR-4 (QTL for radicle length under sucrose stress) on chromosome 4, respectively, 23, 23 and 26% of phenotypic variation for coleoptile and root length were justified in terms of osmotic stress. This QTL explained that due to the high percentage of candidates for marker-assisted selection programs recombinant line population of Iranian rice.