大气CO2浓度和温度升高对水稻地上部干物质积累和分配的影响

摘要

应用增温-FACE（Elevated temperature and CO2-free air controlled enrichment，T-FACE）试验平台，研究了CO2浓度升高（比对照高200µL·L-1）和增温（比对照高1℃）对常规粳稻（Oryza saliva subspkeng）武运粳23不同部位干物质积累与分配的影响。结果显示，2013年水稻季平均气温比2014年高3℃以上，尽管两年CO2浓度升高或增温对水稻地上部干物质积累的影响趋势一致，但对不同时期干物质的影响程度有所不同，表现为CO2浓度升高使2013年拔节-孕穗期和2014年成熟期水稻地上部干物质的积累显著增加40%和16.7%；增温使2013年灌浆期和2014年拔节-孕穗期地上部干物质显著减少14.6%和21.7%。CO2浓度与温度升高对水稻地上部干物质积累的影响存在年际差异，主要与2013年穗中干物质减少而2014年穗中干物质增加有关。2013年不同处理下水稻各部位干物质分配不存在明显差异，2014年高浓度CO2与CO2浓度和温度同时升高降低了灌浆期水稻营养器官而提高了生殖器官中干物质的分配比例，增温并未使干物质在茎叶穗中的分配比例出现显著差异。同时，收获期水稻籽粒产量的变幅与地上部总干物质的变幅存在显著的正相关关系（r2=0.911）。研究表明，整体上高浓度 CO2提高了而增温降低了干物质在水稻不同器官中的积累，二者共同作用对水稻干物质积累与分配的影响存在一定的年际效应，主要是因为气候条件的差异而导致干物质在稻穗中的积累不同。此外，不同处理下干物质在稻穗中的积累及分配影响产量的形成。%To investigate the effects of elevated CO2 concentration (+200 µL·L-1) and elevated temperature (+1℃) on the accumulation and distribution of dry matter (DM) in rice (Oryza Sativa L.), a field experiment was carried out under the Temperature and CO2-Free Air Controlled Enrichment (T-FACE) condition. The results showed that although similar trend was observed for the accumulation of aboveground DM, the extent of changes affected by elevated CO2 or elevated temperature varied at different stages in two years because three degrees Celsius was higher in 2013 than in 2014 on the average air temperature. Specifically, the CO2-induced increase on the aboveground DM at jointing-booting stage in 2013 was 40% and it was 16.7% at mature stage in 2014. On the contrary, significant reduction of 14.6% and 21.7% appeared at the filling stage in 2013 and at jointing-booting stage in 2014, respectively, under elevated temperature. The interannual difference for the aboveground DM under the combination of elevatedϕ(CO2) and temperature was mainly depended on the DM in panicle which was decreased in 2013 and increased in 2014. No significant differences for the DM distribution in separate organ were observed under different treatments in 2013. However, elevatedϕ(CO2) and the combination with temperature declined the DM distribution of vegetative organs and increased that in reproductive organ at filling stage but elevated temperature did not significantly affect the DM distribution in rice organs in 2014. Meanwhile, positive relationship (r2=0.911) existed in the variation between grain yield and aboveground DM at harvest period. All these demonstrated that high CO2 concentration enhanced but elevated temperature reduced the DM accumulation in different organs of rice on the whole. The interannual effects for the accumulation and distribution of DM appeared under the combination of elevatedϕ(CO2) and temperature due to the differences of air temperature in two years, which led to the different accumulation of DM in panicle of rice. In addition, the accumulation of DM in panicle under different treatments closely affected the formation of yield.