QTLs Mapping for Agronomic Traits in RIL of Japonica Cultivar×Japonica Weody Rice

A population of recombinant inbred lines derived from a cross between Ilpumbyeo, a blast-susceptible japonica cultivar of high eating-quality and high yield potential, and GL33, a blast-resistance japonica weedy rice was used to identify QTLs affecting important agronomic traits. A total of putative fourteen QTLs were identified, of which nine QTLs were from Ilpumbyeo alleles, and five were from GL33 alleles. The percentage of phenotypic variance explained by each QTL ranged from 6.4% to 30.2% with an average of 12.5%. Of three QTLs detected for days to heading, qhd3 and qhd7 from GL33 functioned to shorten the days to heading time by GL33 alleles. Three QTLs, qsnpp7 for spikelet number per panicle, qpgr6 for percentage of grain ripening and qyi11 for yield have not been detected in the previous QTLs studies. A QTL qcl1 for culm length explaining 23.6% of phenotypic variation on chromosome 1 was identified at the region of sd-1 gene. Some QTLs, especially for yield component traits on chromosome 1, 3, 6 and 7 were clustered together froming QTL blocks. These QTL blocks seemed to be useful for marker-assisted selection in japonica rice breeding program.