Fine Mapping of qTGW3-1, a QTL for 1000-Grain Weight on Chromosome 3 in Rice

The QTL qTGW3-1 was located on chromosome 3 of rice (Oryza sativa L.) and associated with the 1000-grain weight (TGW) according to the result of our earlier study. With the objective of fine mapping of this locus, we developed a F2 population consisting of 3 428 plants derived from the cross between TGW-related near isogenic line DL017 (BC3F4 generation of GSL156×Nipponbare) and the recurrent parent Nipponbare. Using six microsatellites, this QTL was delimited between RM5477 and RM6417. Markers MM1455 and MM1456 within this region were used for further mapping of this QTL. Finally, qTGW3-1 was fine-mapped into a 89-kb interval between RM5477 and MM1456, which locates in the BAC clone AC107226 harboring five putative candidate genes.