Abstract: A thermo-sensitive virescent rice mutant was identified from M2 of Nipponbare by 60Coγ radiation, temporarily named as v5(virescent 5). The leaf color of the mutant is yellow at lower temperature (20-24℃) while turning to nearly normal green at higher temperature (26-30℃). The chlorophyll content of the mutants was significantly lower than wild-type plants under lower temperature. The agronomic traits showed that the yield of individual mutant was significantly lower than wild-type. It was revealed from the genetic analysis that it was a single nuclear-encoded recessive gene. It's responsible for the mutation and mapped on chromosome 9. A high-resolution physical map of the chromosomal region around the OsV5 gene was then constructed using F2 population (v5/Kasalath) and the gene was finally located on the region of 166.5 kb between the marker STS1 on the BAC AP005838 and the marker STS5312 on the BAC AP005702.

Key words: rice, v5, thermo-sensitivity, virescent, gene mapping