Positional cloning of a major quantitative trait locus controlling low temperature germinability in rice

Abstract

Tolerance to abiotic stress is an important agronomic trait in crop and is a complex trait controlled by many genes, which is called quantitative trait loci (QTLs). Identification of these QTLs would archive a stable crop production in the world. Previously, we mapped three QTLs controlling low temperature germinability using back crossed inbred lines (BILs) derived from a cross between a vigourous low temperature germinability temperate japonica variety, Italica Livorno, and a normal temperate japonica variety, Hayamasari. A major QTL, qLTG-3-1, low temperature germinability on chromosome 3, explained more than 30 % of total phenotypic variation in the mapping population. To understand the molecular basis of the most effective QTL, qLTG-3-1, we identified it by positional cloning method and found that it encoded unknown function protein.