COMPARISON OF QTL AND BULKED LINE ANALYSIS (BLA) FOR MAPPING OF RF GENE IN RICE

¹ DNA Fingerprinting Unit, National Center for Genetic Engineering and Biotechnology at Kasetsart University, Kamphangsaen, Nakorn Pathom 73140, Thailand

² Rice Research Institute, Yunnan Agricultural University, Kunming 650201, China

A method, bulked line analysis (BLA), was developed for rapid identification of RFLP markers linked to a target gene. Instead of using segregating progenies, breeding lines were bulked according to common traits of interest. One hundred and eighty RFLP markers covering 12 rice chromosomes were screened against DNA from the B-line and the R-line pools. One RFLP marker on chromosome 10, RG134, showed a positive result. More RFLP markers on chromosome 10 were subsequently used to pin point to the fine location and marker C1361 was closely linked to the Rf gene. When QTL analysis of this trait was performed in a segregation population, two QTLs were detected on the chromosome 10. The major QTL with 71.5% explained phenotypic variance was located in the 0.9 cM interval between C1361 and S10019. The second QTL was located between markers R2309 and RG257 and explained 27.3% of the phenotypic variance. These results suggested that the BLA can be used to detect a major QTL with a large explained phenotypic variance. Therefore, the BLA method can be used as an alternative approach to identify DNA markers linked to the target gene. A major advantage of this method is time saving for development of genetic population for QTL analysis especially for plant with long generation period.