QTL Mapping Of The Yield, The Height And The Heading Date In Rice

Plant height, heading date, the size and the shape of grain are very importantagronomy traits in rice (Oryza sativa L.) which are adapted to cultivated areas,appropriate seasons and attain an ideal yield, and these agronomy traits are the leadingobjectives of rice improvement programs. Therefore, these genes that are mapped andcloned controlling agronomic traits in rice,and then are studied on genetic regulatorymechanism for plant height, heading date,grain weight and grain shape in rice areuseful for rice breeding and productive practice. In this study, we analyze severalQTLs controlling several important agronomy traits:High generation backcross method and marker-assisted selection are used tobuild the single segment substitution lines. Genetic background of this material issimilar to genetic background of the receptor. Only one segment of this material arefrom the donator. An F2secondary separation group named group A from ahybridization between SSSL W01-42-42-8-20-1and Huajingxian74was developed.Another F2secondary separation group named group B from a hybridization betweenSSSL W06-40-48-06-2-1and Huajingxian74was developed. In the group A, therewere two group: late heading plants and early heading plants. The number segregationratio conforms with1:15, and we think two genes controlling heading date werefound in W01-42-42-8-20-1, manifesting two major dominant genes leaded tocharacter segregation of group A. Making use of Molecular Genetic Markers, thelocus was delimited between marks RM510and RM204. And two cloned genescontrolling the heading date were found between marks RM510and RM204in Oryzasativa L., respectively Hd3a and RFT1. Citing the experimental result of another staffmember in this study, the protein sequences and DNA sequences of Hd3a weredifferent in HJX74and in single substitution lines. The protein sequences and DNAsequences of RFT1were different in the two materials. This study may prove that thetwo genes (Hd3a and RFT1) control the heading stage in separate group A. Using the group B, a QTL for height, a QTL controlling1000-grain weight (KGW), a QTLcontrolling grain shape (GS) were identified with QTL substitution mapping analysisin W06-40-48-06-2-1. The individuals were used as material which agronomiccharacters were significant different with agronomic characters of Huajingxian74.Mapping of quantitative trait loci (QTL) was used to research the heading date ofplant from an advanced backcross population consisted of246plants that were builtfrom the hybridization between Shengdao16and9311. Shengdao16was the recurrentparent and these materials were acquired after four generations of backcross. Thismapping of quantitative trait loci was used by bulked segregating analysis andpolymorphic microsatellite marker analysis. In this group, the number segregationratio of late and early heading plants conformed with1:3, manifesting a majordominant gene leaded to character segregation of this group. The locus was delimitedto a4.0cM interval between marks PSM388and RM19895in chromosome6.