不同浓度MeJA对头花蓼光合和荧光特性的影响

Effect of Different Concentration of Methyl Jasmonate on Leaf Photosynthesis and Fluorescence of Polygonum capitatum Buch.-Ham. ex D. Don.

以苗药头花蓼为研究对象,对其在不同浓度茉莉酸甲酯处理下叶片的光合和荧光特性进行了研究,以期能够为外源物质在头花蓼栽培过程中的应用提供理论依据。结果表明:当茉莉酸甲酯(MeJA)在0~7.5 mmol/L范围内变化时,头花蓼的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间二氧化碳浓度(Ci)、实际量子产量(Y(Ⅱ))、最大光量子产量(Fv/Fm)、最大荧光(Fm)、光化学猝灭系数(qP)均呈现先上升后下降趋势,初始荧光(F0)呈现上升趋势,非光化学猝灭系数(NPQ)呈现下降趋势,Ci极值出现在0.1 mmol/L,而Pn、Gs、Tr、Ci、Y(Ⅱ)、Fv/Fm、Fm、qP出现在0.5 mmol/L处,当MeJA浓度低于0.5 mmol/L,F0与NPQ变化不明显,当MeJA浓度超过0.5 mmol/L时,F0与NPQ变化明显。综上分析,0.5 mmol/L茉莉酸甲酯明显提高头花蓼的光合效率,超过0.5 mmol/L后,茉莉酸甲酯不会对头花蓼光合系统有显著的伤害,Pn虽然呈下降趋势但是与气孔因素有关。

Using pot-cultured Polygonum capitatum Buch.-Ham.ex D.Don as materials,effect of different concentration of Methyl Jasmonate(MeJA)on photosynthesis and chlorophyll fluorescence characteristics of leaves was studied in the paper.The result showed that Pn,Gs,Tr,Ci,Y(Ⅱ),Fv/Fm,Fm and qP of Polygonum capitatum Buch.-Ham.ex D.Don increased at first,and then decreased when the concentration of MeJA changed among 0-7.5 mmol/L.F0 has increasing tendency and NPQ has a decreasing tendency.When the MeJA concentrations was 0.5 mmol/L,Pn,Gs,Tr,Y(Ⅱ),Fv/Fm,and Fm were the highest.However,Ci was the highest when MeJA concentrations was 0.1 mmol/L.If MeJA concentration was lower than 0.5 mmol/L,the F0 and NPQ was stable.F0 increased and NPQ decreased when MeJA concentration was 0.5 mmol/L to 7.5 mmol/L.In summary,the data presented in the paper suggested that MeJA treatment of 0.5 mmol/L might significantly enhance the photosynthetic efficiency of Polygonum capitatum Buch.-Ham.ex D.Don.The concentration of MeJA higher than 0.5 mmol/L did not cause significant damage to the photosynthetic system of Polygonum capitatum and the decrease of Pn was related to stomatal factors at this time.