空气中CO2浓度升高条件下水稻抽穗期的QTL定位

以65个水稻染色体片段置换系(chromosome segment substitution lines，CSSLs)为材料，对比分析了正常大气CO2浓度（对照）和开放式空气CO2浓度升高（free air CO2 enrichment，FACE,大气CO2浓度增加200 μmol/mol）下水稻抽穗期的变化，并定位了相关QTL(quantitative trait loci)。供试株系的抽穗期对CO2浓度升高表现为提早、延迟和不变等3种响应，抽穗期两极变化最大的株系为AI46（提前11 d）和AI63（延迟6 d）。两种条件下，共检测到9个控制抽穗期的QTL，分布在第3、4、6、7、8、10和11染色体上。其中位于第6和第8染色体上的 qHD6 4和 qHD8 4在两种CO2浓度下都检测到，但在FACE下的贡献率均显著增大；而 qHD3A 3和 qHD11A 7只在正常条件下检测到， qHD4F 4、 qHD10F 4和 qHD11F 4则只在FACE下检测到。 暗示控制水稻抽穗期的基因表达易受环境CO2浓度的影响。

QTL Analysis for Heading Date of Rice under Free Air CO2 Enrichment Conditions

A mapping population consisting of 65 chromosome segment substitution lines(CSSLs) was used to detect quantitative trait loci (QTL) for heading date of rice !(Oryza sativa L .) under the ambient atmosphere CO₂ concentration (Ambient) and free air CO₂ enrichment (FACE, ambient + 200 μmol/mol) conditions. Both positive and negative responses to elevated CO₂ at heading date of CSSLs were found. Among them, two CSSLs, AI46 (advanced 11 days) and AI63 (delayed 6 days), were the most sensitive to elevated CO₂ in different directions. A total of 9 QTLs for heading date were detected on chromosomes 3, 4, 6, 7, 8, 10 and 11 under the FACE and Ambient. Of them, qHD6-4 and qHD8-4 were simultaneously detected under both the FACE and Ambient, but the percentage of variation explained under the FACE was much higher than that under the Ambient, in addition, two QTLs, qHD3 A-3 and qHD11 A-7 were only detected under Ambient, and three QTLs, qHD4 F-4 , qHD10 F-4 and qHD11 F-4 only under FACE, suggesting that the genes affecting heading date were sensitive to atmosphere CO₂ concentration.