锌胁迫对汉麻光合特性及叶绿素荧光参数的影响

目的]研究汉麻在重金属锌胁迫下的光合特性及叶绿素荧光参数的响应。方法]通过温室水培试验,研究不同浓度锌胁迫对汉麻光合特性及叶绿素荧光参数的影响。结果]与2μmol/L锌浓度处理(CK)相比,缺锌0μmol/L和高浓度锌处理(50、100、200μmol/L)的汉麻,其叶片的叶绿素a、叶绿素b和类胡萝卜素均下降,叶绿素a减少速率最快;高锌处理随着锌浓度的增加,净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)呈下降趋势,胞间二氧化碳浓度(Ci)缓慢上升。胁迫40 d后,高锌处理的PSⅡ原初光能转化效率(Fv/Fm)、实际光量子产量(Y)、光化学淬灭系数(q P)、光合电子传递速率(ETR)随锌浓度的升高呈下降趋势,非光化学荧光猝灭系数(NPQ)在200μmol/L锌浓度水平下胁迫10 d后取得最大值,而后随时间延长而迅速衰减,叶绿素b与非光化学荧光猝灭机制对汉麻的光合作用起重要保护作用。结论]锌对汉麻光合机制有明显的影响,缺锌和高浓度锌对汉麻光合代谢过程有抑制和损害。

Effects of Zinc Stress on Photosynthesis and Chlorophyll Flouorescence Characteristics of Cannabis sativa L.

Objective] The aim was to investigate the effects of zinc stress on photosynthesis and chlorophyll flouorescence characteristics of Cannabis sativa. Method] The effects of different concentrations of zinc on the photosynthesis and chlorophyll fluorescence characteristics of C. sativa were studied with a solution culture.Result] The results showed that with the increase of zinc concentration,the levels of chlorophyll a, chlorophyll b and carotenoids decreased,and the reduction orate of chlorophylla was the fastest compared with 2 μmol zinc treatment(CK).For the plants under zinc stress,net photosynthetic rate (Pn),transpiration rate (Tr) and stomatal conductance (Gs) showed a downward tendency as the concentration of Zn increased,while intercellular CO2 concentration (Ci) increased.During the stress process,(Fv/Fm),actual quantum yield (Y),photochemical quenching coefficient(qP),and electron transport rate (ETR) decreased.The non -photochemical quenching coefficient (NPQ) reached its maximum value at zinc level of 200μmol/L on the 10th day,and then rapidly decay over time.The zinc tolerance of C.sativa was related to the protection mechanism of chlorophyll b and non-photochemical quenching coefficient. Conclusion] Zinc had significant effects on photosynthetic mechanism of C.sativa.The process of photosynthesis and metabolism was inhibited and damaged under zinc deficiency and high concentration of zinc.