QTL identification for salt tolerance related traits at the seedling stage inindicarice using a multi-parent advanced generation intercross (MAGIC) population

摘要

Salinity is one of the most important abiotic stresses, which seriously affects rice production. In this study, a multiparent advanced generation intercross population, DC1, derived from intercrossing four eliteindicavarieties, was used to identify QTLs conferring salt tolerance. The whole population and four parents were genotyped with a 55K rice SNP array. A total of 7 QTLs delineated from 186 significant marker-trait associations were detected on chromosomes 1, 2, 5 and 9, which accounted for 7.42-9.38% of the total phenotypic variations. Among these QTLs, one novel QTL (qRRL2) on chromosome 2 for relative root length and one multi-trait QTL (qSLST1/qRDSW1/qRB1) on chromosome 1 affecting shoot length, root dry weight and root biomass under salt treatment were detected. Gene expression analysis revealed that a transcription factor gene (LOC_Os01g66280) within the multi-trait QTL is the potential candidate gene for salt tolerance. Interestingly, we identified one significant nonsynonymous SNP in the coding region of this candidate gene. These results will facilitate fine mapping of the candidate gene and QTL pyramiding to genetically improve salt tolerance in rice.