[Discovery of QTLs increasing yield related traits in common wild rice]

Common wild rice (Oryza rufipogon) is an important genetic resource. Discovery of desirable alleles in wild rice will make important contributions to rice genetic improvement. In this study, Zhenshan 97 as the recurrent parent and wild rice as the donor parent were used to develop a BC2F1 population. One plant BC2F1-15 in the population showed distinct phenotype from Zhenshan 97 was selected to produce a population of BC2F5 by continuous self-crossing. The genotype assay of the plant BC2F1-15 with 126 polymorphic SSR markers evenly distributed on 12 chromosomes showed that it was heterozygous at 30% of the control marker loci. Four, 3, 4, 2, and 1 QTLs were detected for heading date, plant height, spikelets per panicle, grain weight, and single plant yield in the BC2F5 population, respectively. One QTL region flanked by the marker interval of RM481-RM2 on chromosome 7 had pleiotropic effects on heading date, spikelets per panicle, and grain yield per plant, and the alleles of wild rice increased phenotypic values. At the other 3 QTLs for spikelets per panicle, common wild rice had positive effects. These results clearly showed that common wild rice carried desirable alleles for yield related traits. The favorable alleles from common wild rice are new valuable genes for rice breeding.