水稻基部伸长节间性状与倒伏相关性分析及QTL定位

Relationship between Traits of Basal Elongating Internodes and Lodging and QTL Mapping in Rice (Oryza sativa L.)

利用珍汕97B密阳46RILs群体及其构建的连锁图谱,对水稻株高和基部Ⅰ、Ⅱ伸长节间性状与稻株抗倒伏能力进行相关分析,并对基部Ⅰ、Ⅱ伸长节间性状进行QTL定位,共检测到加性效应QTLs16个、加性×加性互作33对。估算了每个QTL的加性效应值和每对加加互作的上位性效应值,比较了QTLs的基因组分布。在第1染色体短臂和第6染色体短臂等基因组区域,在相同或相近区间检测到控制相关性状的多个QTLs,其中以第6染色体短臂RM197RZ516区间尤为突出,所检测到的QTLs影响除第Ⅱ伸长节间长以外的其余6个性状。

Lodging has negative effects on the yield, grain quality and mechanical harvesting efficiency in the rice production. Although it has been well recognized that characters of the basal Ⅰ,Ⅱ elongating internodes are significantly correlated to lodging tolerance in rice, little work was done on the inheritance of these traits. In the present study, a recombinant inbred lines (RILs) population consisting of 247 lines derived from an indica-indica rice cross Zhenshan97B/Milyang46 was used to detect quantitative trait loci (QTL) conditioning lodging tolerance-related traits in rice. In 2003, the 247 RILs, as well as the parental lines, were grown in the paddy field of China National Rice Research Institute (CNRRI), Hangzhou, China, using random complete block design with 2 replications and 20 plants per line per replication. Plant height (PH) was measured at maturity. Seven traits related to lodging tolerance were scored and used for QTL analysis, including first internode length (FIL), second internode length (SIL), first internode thick (FIT), second internode thick (SIT), first internode weight (FIWu), second internode weight (SIWu)and plant resistance (PR). A linkage map consisting of 207 DNA markers distributing on the 12 chromosomes of rice was employed for QTL mapping by using software QTL Mapper 1.6 of mixed linear model. It was shown that the lodging resistance had significant negative correlations with traits FIL and SIL, whereas significantly positive correlations were observed between lodging resistance and traits FIT, SIT, FIWun, and SIWu (Table 2). No significant correlations were found between PH and PRp. It was indicated that selection of higher FIT, SIT, FIWun and SIWun in rice breeding might be advantageous for enhancing lodging resistance. A total of 16 QTLs showing significant additive effects (Table 3) and 33 significantly additive by additive (AA) interactions (Table 4) were detected. While the contributions to the phenotype variance due to additive effect of a single QTL had a wide range of 4.20%-25.40%, the contributions due to epistatic effect of a single AA interaction showed a smaller range of 2.06%-10.95%. In a number of genomic regions, such as intervals on the short arms of chromosomes 1 and 6, QTLs were detected for two or more traits. The extreme example was found in interval RM197-RZ516 on the short arm of chromosome 6, in which QTLs having significantly additive effects were detected for all traits except SIL.