1,2,4-三氯苯和萘对水稻抽穗期叶片光合特性的影响

Effects of 1,2,4-Trichlorobenzene and Naphthalene Stress on Photosynthetic Characteristics of Rice at Heading Period

研究了1,2,4-三氯苯(TCB)和萘(NAP)对抽穗期水稻叶片光合特性的影响。结果表明,随TCB和NAP胁迫浓度的增加,叶绿素含量、净光合速率(Pn)、气孔导度(Gs)、细胞间隙CO2浓度(Ci)、蒸腾速率(Tr)、原初光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、光合电子传递量子效率(ΦPSII)、光化学猝灭系数(qP)、非光化学猝灭系数(qN)均呈下降趋势;而且TCB对以上指标的影响明显大于NAP的影响,汕优63的敏感性要大于武运粳7号;有机污染胁迫下,光合速率下降的原因,在低浓度时主要由于气孔限制引起,而在较高浓度下由气孔限制和非气孔限制共同引起。较高浓度的有机污染物使光合作用受到明显抑制,最终导致水稻产量显著降低。在各叶绿素荧光动力学参数中,以PSⅡ潜在活性(Fv/Fo)和非光化学猝灭系数(qN)对有机污染胁迫最为敏感。建议将这两个参数作为衡量水稻发生有机污染伤害的参考指标。

The effects of 1,2,4-trichlorobenzene (TCB) and naphthalene (NAP) on photosynthetic characteristics of rice leaves were studied. The results showed that chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), photochemical efficiency (Fv/Fm), quantum yield of PSII (ΦPSII), potential activity of PSII (Fv/Fo) and photochemical quenching (qP) and non-photochemical quenching (qN) decreased under TCB and NAP stress. The effects of TCB were more serious than that of NAP, while the sensitivity of Shanyou 63 was higher than that of Wuyunjing 7. Under low concentration of organic pollutants, stomatal limitation was a dominating factor for Pn decrease. Under high concentration of organic pollutants, the decrease of Pn was due mainly to stomatal limitation and the non-stomatal limitation. High concentration of pollutants suppressed the synthesis more strongly, and finally reduced the grain yield. Among all of the chlorophyll fluorescence kinetics of parameters, both Fv/Fo and qN are more sensitive to TCB and NAP than the other parameters. Therefore, both Fv/Fo and qN would be the sensitive reference indicator of harm of organic pollutants on rice.