水稻产量及其构成因子对空气CO2浓度增高响应的QTL分析

自由空气CO2浓度增加设施（Free air carbon dioxide enrichment．FACE）使得实际地模拟未来植物生长所处的CO2浓度增加环境变为可能。FACE下．作物生长和产量发生不同程度的加速和提高，而分析作物产量因子对CO2浓度增加响应的遗传基础将有利于对CO2环境变化做出敏感响应的遗传特性的认识，有利于适合未来空气CO2浓度增加环境的高产品种的培育。以粳稻品种Asominori与籼稻品种IR24的杂交组合所衍生的染色体片段置换系（CSSLs）为材料进行田间试验，分别在FACE（约570umol CO2／mol）和正常大气（约370umol CO2／mol）下对籽粒产量及其构成因子等数量性状位点（QTL）进行了分析。结果表明，在FACE下，Asominori和IR24的有效穗数、穗粒数和单株籽粒产量均显著高于对照下的，并且FACE下，65个置换系的变幅范围均大于对照下的；在第1．2，4，6．7，9和12染色体上检测到LOD值在2．5—5．7范围内的控制上述产量性状的20个QTL．其中有3个可以同时在FACE和正常大气下检测到．其余的则只是在某一种CO2环境下检测到。此外，还检测到2个QTL（qFT12 and qGP4）存在着与环境的加性互作效应。可以推论．空气中CO2浓度的增加诱导了部分对CO2浓度敏感的QTL表达，控制水稻产量性状的QTL与CO2增加的环境发生了互作效应。预计利用分子标记辅助育种途径可以培育出适用于未来CO2浓度增加环境下的高产水稻品种。

QTL for Yield and Its Components Responded to Elevated CO2 in Rice (Oryza sativa L. )

FACE (free air carbon dioxide enrichment) technology may provide a means by which the environment around growing plants can be modified to realistically simulate the concentration of atmospheric CO2 in the future. The plant growth and its yield of plant species can be enhanced under FACE. Identification of genomic regions influencing the response of yield and its components to elevated CO2 will be useful for understanding the genetics of active response to changed CO2 environment and developing higher yield cultivars,which will be adapted to future enriched atmospheric CO2 environment. A mapping population of 65 indica ( IR24) chromosome segment substitution lines (CSSLs) in japonica (Asominori) background and their parents were used to detect QTLs for yield and its components, e. G. Number of fertile tillers per plant (FT), 1 000-grain weight (TGW),number of grains per panicle (GP) and grain yield per plant (GY) under FACE (200 μmol CO2/mol above current levels) and current CO2 concentration (Ambient,about 370 μmol CO2/mol) in the field experiment. The results showed that,GY,GP and FT of two parents under FACE were significant greater than that under Ambient.The transgressive segregation of the four traits was observed in the CSSLs population under both FACE and Ambient. A total of 20 QTLs for the four traits were detected on chromosome 1,2,4,6,7,9 and 12 with LOD (Log10-likelihood ratio) of QTLs ranging from 2.5 to 5.7. Three QTLs were detected under both FACE and Ambient. However,other QTLs were detected only under one level of CO2 ,which indicated that these loci were sensitive to CO2 concentration. Additionally,two QTLs qFT12 and qGP4 were found for the QTL × Environment (QE) interaction effects. It is suggested that there is a high possibility to improve the yield of rice under elevated CO2 through marker-assisted selection.