探讨外源镉（Cd）和温度变化对水稻抽穗期光合特性的影响，为水稻生长过程中应对稻田土壤重金属污染和气候变暖的复合作用提供理论依据。通过添加外源Cd （0和2 mg/kg土）和模拟温度（白天/夜晚分别为30℃/25℃（CK）、33℃/28℃（T1）、36℃/31℃（T2）），研究外源Cd和温度变化对不同品种水稻（武运粳30号和新两优6号）抽穗期光合参数、荧光参数及其生物量的影响。结果表明，单一Cd处理显著降低了新两优6号的SPAD值，而单一增温处理则显著降低了武运粳30号的SPAD值（P<0.05）。虽然外源Cd和温度的复合作用未显著影响武运粳30号和新两优6号的净光合速率（P_n），但Cd处理显著降低了两品种的P_n，而增温处理则显著影响了新两优6号的P_n；大部分Cd和温度处理下，新两优6号的SPAD值和P_n大于武运粳30号。Cd处理和增温处理均影响了水稻叶绿素诱导动力学曲线的形状，O、K、J和I点的荧光因处理的不同而具有一定差异。Cd处理和增温处理对水稻F_v/F_m和比活度参数的影响与水稻品种有关，Cd处理未显著影响运粳30号和新两优6号的F_v/F_m值，而增温处理则显著减少了武运粳30号的F_v/F_m值；新两优6号的比活度参数ABS/RC、DIo/RC、TRo/RC、ET0/RC在Cd处理下显著降低，而武运粳30号的比活度参数在增温处理下则显著增加（P<0.05）。Cd处理显著降低了新两优6号的茎叶生物量，而增温处理则显著降低了武运粳30号茎叶生物量，然而两者的复合作用对水稻茎叶和根生物量的影响因品种不用而具有差异，新两优6号的茎叶和根干物质量在大部分处理下大于武运粳30号。综上可知，Cd和增温处理通过影响水稻的光合参数和荧光参数，从而影响水稻的生物量，但影响程度因品种不同而具有差异，其中，武运粳30号对Cd具有较强的抗性而新两优6号对增温有较强的抗性。因此，在实际的田间管理中，应选择合适的水稻品种，以应对土壤Cd污染和温度升高对水稻生长的影响。

The effects of exogenous cadmium (Cd) and temperature change on photosynthetic characteristics of rice plants were studied in order to provide a theoretical basis for the coping with the combination of soil Cd pollution in rice field and the climate warming during rice growth. Photosynthetic parameters, fluorescence parameters and biomass of different rice cultivars (Wuyungeng 30 and Xinliangyou 6) at heading stage were determined and the fluorescence kinetic curves of rice were analyzed under the condition of adding exogenous Cd (0 and 2 mg/kgsoil) and artificially simulating temperature (daytime/nighttime 30℃/25℃, CK; 33℃/28℃, T1; 36℃/31℃, T2). The results showed single Cd treatment had significant effect on SPAD values of Xinliangyou 6, while single warming treatment significantly reduced SPAD value of Wuyungeng 30. Although the combined effects of Cd and temperature didn't significantly affect the net photosynthetic rate (P_n) of Wuyungeng 30 and Xinliangyou 6, single Cd treatment significantly reduced P_nof the two rice cultivars and single warming treatment significantly affected P_n of Xinliangyou 6. The shape of chlorophyll fluorescence induction kinetics (O-J-I-P) was affected by Cd and warming treatment. Fluorescence in O, K, J and I were different with different treatments. Effects of Cd and warming treatment on F_v/F_m and specific activity parameters were related to rice cultivars. Cd treatment did not significantly affect the F_v/F_m of Wuyungeng30 and Xinliangyou 6, while single warming treatment significantly reduced F_v/F_mof Wuyungeng 30. Cd treatment significantly reduced specific activity parameters ABS/RC, DIo/RC, TRo/RC and ET0/RC of Xinliangyou 6 (P<0.05), while warming treatment significantly increased specific activity parameters of Wuyungeng 30. Single Cd treatment significantly reduced the aboveground weight of Xinliangyou 6, while single warming treatment significantly reduced the aboveground weight of Wuyungeng 30. However, the combined effects of Cd and warming on the biomass of rice varied with rice varieties. In conclusion, Cd and warming affect the biomass of rice by affecting the photosynthetic parameters and fluorescence parameters of rice, but the degree of influence varies with different cultivars. Among them, Wuyungeng 30 has strong resistance to Cd, while Xinliangyou 6 has strong resistance to warming. Therefore, suitable rice varieties should be selected in actual field management to cope with the effects of soil Cd pollution and temperature rise on rice growth.

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江苏省农业气象重点实验室开放课题项目（KYQ1402）资助。