Mapping QTLs for Salt Tolerance at Seeding Stage of Landrace Rice (Oryza sativa L.).

[Objectives] The identification of salt tolerant genetic loci in rice can provide a research basis for the molecular mechanism of salt tolerance and gene resources for improving salt tolerant cultivars. [Methods Recombinant inbred lines (RILs) derived from Zhaxima, an indica landrace variety from Yunnan Province and Nanjing 46, an elite japonica variety with superior grain quality from Jiangsu Province were used. The salt tolerance at seeding stage in the RIL population was investigated as the phenotypic value. [Results] Combined with the linkage map, a total of 4 QTLs were detected: qSST-1 , qSST-3, qSST-5 and qSST-11, located in rice chromosomes 1,3,5 and 11 , respectively. All positive alleles were from the parent Nanjing 46. Three QTLs among them were not included in chromosome intervals the same as cloned rice salt tolerance genes, and thus were described as new candidate gene loci associated with seeding-stage salt tolerance. [Conclusions] This study provides important information for further exploration and utilization of new salt tolerant QTLs in rice. It is of great significance for improving the utilization of saline land in China and ensuring the stable rice production. [ABSTRACT FROM AUTHOR]