水稻幼苗耐缺氧能力的QTL分析

QTL Analysis of the Anoxic Tolerance at the Seedling Stage in Rice

利用粳稻品种秀水79与粳稻恢复系C堡及其衍生的247个重组自交系(RIL)和粳稻Nipponbare与籼稻Kasalath及Nipponbare/Kasalath//Nipponbare衍生的98个回交重组自交系(BIL)为材料,在缺氧胁迫和正常萌发条件下调查了萌发7d的幼苗芽鞘长度。以缺氧反应指数为衡量指标,对幼苗耐缺氧能力进行了QTL分析。RIL群体在第2染色体上检测到1个与SSR标记RM525紧密连锁的QTLqSAT-2-R,解释表型变异的8.7%;在第7染色体上检测到1个与RM418紧密连锁的QTLqSAT-7-R,解释表型变异的9.8%;增效等位基因均来自C堡。BIL群体检测到6个QTL,分布在第2、3、5、8、9和12染色体上,分别解释表型变异的16.2%、11.4%、7.3%、5.8%、9.5%和14.0%;其中qSAT-2-B、qSAT-3-B和qSAT-9-B增效等位基因来自Nipponbare。与qSAT-2-B紧密连锁的RFLP标记为C747,C747对应SSR标记RM1367;qSAT-2-R与qSAT-2-B相距7.2cM。

Coleoptile lengths（CL） of seedlings at 7 days after germination under anoxic stress and normal conditions were inves tigated in two permanently segregated populations and their parents in rice （Oryza sativa L. ）. By using anoxic response index, a ratio of CL under anoxic stress to CL under normal conditions, as indicator of seedling anoxic tolerance （SAT）, QTLs for SAT were detected. Two loci controlling SAT, designated as qSAT2 R and qSAT-7-R, were detected in the RIL population （247 lines） derived from a cross between Xiushui 79（japonica cuhivar） and C Bao（japonica restorer line）, qSAT-2-R, explaining 8.7% of phenotypic variation, was tightly linked with the SSR marker RM525. qSAT7 R, explaining 9.8% of phenotypic variation, was tightly linked with the marker RM418. The positive alleles of the two loci came from C Bao. Six loci controlling SAT, designated as qSAT-2-B, qSAT-3-B, qSAT-5 B, qSAT8 B, qSAT-9-B and qSAT-12-B, were detected in the BIL population （98 lines） derived from a backeross of Nipponbare （japonica） /Kasalath （indica）//Nipponbare（japonica）. The positive alleles of qSAT-2-B, qSAT-3-B and qSAT9 B, which explained 16.2%, 11.4% and 9.5% of phenotypic variation, respectively, came from Nipponbare. The positive alleles qSAT5 B, qSAT-8-B and qSAT-12-B, which explained 7. 3%, 5.8% and 14.0% of phenotypie variation, respectively, were from Kasalath. The RFLP marker C747, linked tightly with qSAT-2-B, corresponded to the SSR marker RM1367 according to physical map. Genetic distance between aSAT2 R and qSAT-2-B was 7.2 cM.