水稻千粒重对大气CO_2浓度升高的响应

Response of 1 000-grain Weight to FACE in CSSL Population of Rice (Oryza sativa L.)

以65个水稻染色体片段置换系(CSSL,chromosomesegmentsubstitutionlines,以Asominori为背景,置换片段来自IR24)为材料,对比分析了正常大气CO2浓度(对照)和FACE(FreeAirCO2Enrichment,大气CO2浓度增加200μmol·mol-1)下千粒重的变化及其QTL(quantitativetraitloci)定位。结果表明,FACE下,供试株系千粒重的增长率变化幅度为-12.31%～14.51%,呈正负两种响应,其中置换系AI8和AI61及AI10和AI41的变幅最大,分别达极显著和显著水平;共检测到控制千粒重性状的5个QTL,分别分布在第1、7和10条染色体上。其中1个qGWT-10位于第10染色体上的是在两种CO2浓度下都检测到的位点相同但贡献率和加性效应值不同的QTL,其余的分别在FACE或对照下检测到;qGWT-1F和qGWT-7F只在FACE下检测到,说明控制水稻千粒重的基因表达易受环境CO2浓度的影响,这些对CO2浓度响应敏感的基因可能存在于第1和第7条染色体。

Since the industrial revolution, the CO_2 concentration in the atmosphere has increased from approximately 280 μmol·mol^(-1) to about 370 μmol·mol^(-1) today. It is expected that atmospheric CO_2 levels will continue to rise, and during the century could well exceed 500, even over 550 μmol·mol^(-1). FACE stands for Free Air CO_2 Enrichment. FACE technology is capable of providing a means by which the environment around growing plants may be modified to realistically simulate future concentrations of atmospheric carbon dioxide (CO_2). Few studies have evaluated elevated CO_2 responses of 1 000-grain weight (GWT). This study was conducted to determine the different genetic effects controlling GWT of rice (Oryza sativa L.) under ambient atmosphere CO_2 concentration (CK) and FACE (ambient + 200 μmol·mol^(-1)), which may be useful for rice breeding in future. A mapping population of 65 indica (IR24) chromosome segment substitution lines (CSSLs) with japonica (Asominori) background was used to detect quantitative trait loci (QTL) for GWT under CK and FACE. The main results indicated that the increasing rates for GWT of CSSL were ranged from -12.31% to 14.54% presenting nearly a normal school under FACE in compared with that under CK (Fig.1). Among of them, those increasing rates of GWT in the CSSL AI8, AI61 and CSSL AI10 and AI41 under FACE were most different from CK significantly at 1% and 5% level respectively (Table 1). As compared with CK, the rate of increasing of GWT in CSSL AI8, AI10, AI41 and AI61 under FACE, increased by 14.32%, 14.51%, -7.08% and -12.32%, respectively. A total of 5 QTLs for GWT were detected on chromosome 1, 7 and 10 under FACE and CK. qGWT-10 was simultaneously detected under both FACE and CK (Table 2). And its percentage of variation explained and the value of additive were different under FACE and CK. The remained QTLs were detected only under one level of CO_2, especially qGWT-1F and qGWT-7F on chromosome 1 and 7 were detected only in FACE. It can be suggested that the heredity of GWT is affected by CO_2 concentration, and the genes controlling GWT responded to elevate CO_2 might be located in relative region of chromosome 1 and 7.