Discovery Of QTLs Increasing Yield Related Traits In Common Wild Rice And The Construction Of Introgression Lines Using NYZ As The Recurrent Parent And C7 As The Donor Parent

Grain number per panicle,1000-grain weight, heading date and plant height are the important traits to grain yield. It is theoretical and practical significance to study them. However, these agronomic traits are quantitative traits controlled by a number of major and/or minor quantitative trait loci (QTL), with the rapid development of molecular makers, the related QTL can be detected more easily.In this study, Zhenshan 97 as the recurrent parent and wild rice as donor 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 4 continuous self crossing. The BC2F5 population was used to identify QTLs for yield traits. 126 SSR markers evenly distributed to 12 chromosomes were selected to genotype the plant BC2F1-15. Except chromosomes 2,3 and 12 fixed with Zhenshan 97, the other chromosomes each introgressed common wild rice chromosomal segments more or less. 15 QTLs were detected for the yield related traits such as heading date, spikelets per panicle, grain weight, and plant height using single marker analysis and composite interval mapping. Nearby the marker RM567 on chromosome 4, QTLs for heading date, plant height, spikelets per panicle and 1000-grain weight were identified. Nearby the markers RM258 and RM 590 on chromosome 10, there was one QTL simultaneously controlling heading date and spikelets per panicle respectively, but they had opposite effects. In the interval of RM481-RM2 on chromosome 7, one QTL had pleiotropic effects on heading date, spikelets per panicle and grain yield. Allele of wild rice increased phenotypic values. In addition, at the loci of other 3 QTLs for spikelets per panicle, common wild rice had positive effects. These results clearly showed common wild rice carried elite alleles for grain yield. Out of question, the favorable alleles from common wild rice are new valuable genes for rice breeding.Two extremely different parents in phenotype, Nanyangzhan and Chuan7, are used to construct an introgression lines covering nearly whole rice genome, Nanyangzhan is the recurrent parent and Chuan7 as the donor parent for the construction of introgression lines BC4F2 population to identify grain weight and others yield related traits QTLs. The lines with a separation in phenotype are selected and screening its genetic background using molecular markers.15 QTLs (P<0.01) are identified in current population. There are 3 QTLs for grain number per panicle, qGppl, qGpp6 and qGpp8, respectively. Interestingly, qGpp8 have a largest additive effect.2 QTLs for spikelets per panicle on chromosome 3 and 12 respectively; 4 QTLs for plant height, qPh6, qPh7, qPh8 and qPh10, are detected, qPh6 maybe is the major QTL with the largest additive effect. qHd3-1,qHd3-2 and qHd63 are three QTLs for heading date respectively. Besides,3 QTLs for TGW, qTgw2-1, qTgw2-2 and qTgw3 are examined and the alleles from Nanyangzhan may increase the grain weight.