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Theor Appl Genet (2010) 121:895905 DOI 10.1007/s00122-010-1358-x
ORIGINAL PAPER
Fine mapping a QTL qCTB7 for cold tolerance at the booting stage on rice chromosome 7 using a near-isogenic line
Lei Zhou Yawen Zeng Weiwei Zheng Bo Tang
Shuming Yang Hongliang Zhang Jinjie Li
Zichao Li
Received: 18 August 2009 / Accepted: 12 May 2010 / Published online: 30 May 2010 Springer-Verlag 2010
Abstract Low temperature at the booting stage is a serious abiotic stress in rice, and cold tolerance is a complex trait controlled by many quantitative trait loci (QTL). A QTL for cold tolerance at the booting stage in cold-tolerant near-isogenic rice line ZL1929-4 was analyzed. A total of 647 simple sequence repeat (SSR) markers distributed across 12 chromosomes were used to survey for polymorphisms between ZL1929-4 and the cold-sensitive japonica cultivar Towada, and nine were polymorphic. Single marker analysis revealed that markers on chromosome 7 were associated with cold tolerance. By interval mapping using an F2 population from ZL1929-4 9 Towada, a QTL for cold tolerance was detected on the long arm of chromosome 7. The QTL explained 9 and 21% of the phenotypic variances in the F2 and F3 generations, respectively. Recombinant plants were screened for two anking markers, RM182 and RM1132, in an F2 population with 2,810 plants. Two-step substitution
mapping suggested that the QTL was located in a 92-kb interval between markers RI02905 and RM21862. This interval was present in BAC clone AP003804. We designated the QTL as qCTB7 (quantitative trait locus for cold tolerance at the booting stage on chromosome 7), and identied 12 putative candidate genes.
Introduction
Rice (Oryza sativa L.) is one of the three most important food crops in the world. Cold stress is a common problem of rice cultivation, and is a crucial factor affecting global food production. About 30.7 million ha of rice is grown in China and extend over a wide area ranging from 53270N to 18900N. Almost the entire area can be affected by cold injury resulting from low temperatures, and annual losses are 35 million tonnes of rice grain (Li and Guo 1993). Rice is a cold-sensitive plant that has its origin in tropical or sub-tropical areas. Spikelet fertility of rice decreases because the rapidly growing booting and reproductive tissues are...