Abstract:

【Objective】 The objective of the study is to identify quantitative trait loci (QTLs)controlling cold tolerance at seedling stage and linkage SSR markers in Dongxiang wild rice. 【Method】 Cross was made between cold tolerant Dongxiang wild rice (Oryza rufipogon Griff.) and cold susceptible rice variety Nanjing11. Nanjing 11 was then used as the recurrent parent to construct a backcross segregation population (BC2F1) which includes 144 plants. This population was used to detect QTLs for cold tolerance at seedling stage. Root conductivity was used as the index of cold tolerance. The molecular map was constructed with SSR markers and the QTLs for cold tolerance were identified by multiple trait composite intervals mapping. 【Result】 The two QTLs for cold tolerance (qRC-10-1 and qRC-10-2) were detected on chromosome 10, explaining 34.13% and 37.02% of phenotypic variances, respectively. More SSR markers were screened around the region RM171 marker where these two QTLs were located. Three QTLs in regions qRC-10-1 and qRC-10-2 were detected on chromosome 10. 【Conclusion】 qRC-10-1 and qRC-10-2 may be the major QTLs for cold tolerance at seedling stage in Dongxiang wild rice. The location of two QTLs was at the interval RM304 and RM1108 on chromosome 10. The markers in the region between RM304 and RM1108 may be used to select for cold tolerance in rice.

Key words: Dongxiang wild rice, cold tolerance at seedling stage, root conductivity, QTL mapping