不同蚕豆品种对铅污染的光合生理响应特征

以3个蚕豆品种(分别为K0883、K0502、K0697)为试验材料，通过大田模拟小剂量Pb污染(浓度为40和250 mg·kg^-1)，研究了净光合速率、气孔导度、蒸腾速率、细胞间隙CO₂浓度、水分利用效率、叶绿素含量等光合生理响应特征的变化在不同品种中的差异.结果表明，Pb污染下3个蚕豆品种气孔导度和蒸腾速率没有显著变化，叶绿素含量有不同程度的上升；在250 mg·kg^-1 Pb浓度下，K0883蚕豆品种净光合速率、水分利用效率、细胞间隙CO₂浓度分别升高121.80％、上升193.70％、下降42.76％.3个蚕豆品种对Pb污染的抗性大小顺序为K0883＞K0697＞K0502.蚕豆不同光合生理指标对小剂量Pb污染的响应特征不同.不同蚕豆品种对小剂量Pb污染的响应特征存在差异，这种种内的差异性采用单个生理指标难以反映，只有通过对多个指标的整合分析才能表现出来.

Responses of different Vicia faba varieties' photosynthetic characteristics to Pb pollution

In a field experiment of simulated Pb pollution (40 and 250 mg x kg(-1)), this paper investigated the net photosynthetic rate, stomal conductance, transpiration rate, intercellular CO2 concentration, water use efficiency, and chlorophyll content of three Vicia faba varieties K0883, K0502 and K0697. The results showed that under Pb pollution, there was no significant variation in the transpiration rate and stomal conductance of the three varieties, but their chlorophyll content increased in different extents. When the Pb concentration was 250 mg x kg(-1), the net photosynthetic rate and water use efficiency of K0883 were increased by 121.80% and 193.70%, respectively, while its intercellular CO2 concentration was decreased by 42.76%. According to the Perturbation test based on the responses of test photosynthetic characteristics, the Pb-resistance of the three varieties was in the sequence of K0883 > K0697 > K0502. It was concluded that the responses of different photosynthetic indexes and different Vicia faba varieties to small dosage Pb pollution were differed, and the intraspecific difference could only be detected by the integration of all photosynthetic indices.