Summary: | 碩士 === 臺灣大學 === 農藝學研究所 === 98 === Rice grain shape, heading date, plant height and panicle length are the most important factors affecting rice grain quality, yield and adaption area. To detect QTLs controlling grain length (GL), grain width (GW), heading date (HD), plant height (PH), and panicle length (PL), we evaluated two hundred and eighty six F2 individuals derived from the cross between Taiken 2 (TK2) and Taichung Sen 10 (TCS10). Through genotyping all the F2 population, we construct a linkage map with 147 molecular markers including 133 InDel and 14 SSR markers covering all 12 chromosomes in this study. The phenotypic ranges of grain trait in F2 population were between two parents, but the other traits showed transgressive segregation. The correlation between GL and GW are only 0.09. The result of QTL mapping shows that there are 10 and 8 QTLs controlling GL and GW. The PVE of QTLs controlling GL on chromosome 1, 3, 7 are all above 10 %, and GL would increase 0.18 – 0.22 mm by carrying TCS 10 allele. The PVE of QTLs controlling GW on chromosome 2 and 5 are 12% and 44.8%, and GW would increase 0.08 mm and 0.17 mm by carrying TK2 allele. A total 3 QTLs for HD, 5 QTLs for PH and 4 QTLs for PL. The PVE of QTLs on chromosome 3 and 10 controlling HD are around 26%. While these two QTLs carrying TK2 allele, the HD would earlier 6.7 days and delay 6.3 day. The QTL controlling PH on chromosome 1 is the major QTL explained 52.5% of the total variation of PH, and it would increase 14.9 cm with TK2 allele on it. The QTL of PL on chromosome 8 has the largest PVE and would increase 1.5 cm while carrying TK2 allele.
Compare all these result with previous study, the QTL of GW on chromosome 5 might be the GW5 gene, and the QTL controlling HD on chromosome 10 would be Ehd1. The QTL at the long arm on chromosome 1 might be the same as sd-1. All these assumption need to be confirm by functional markers or sequence alignment. All these information would be useful to the rice breeder or have practical used through MAS in rice.
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