黔金荞麦1号保护酶活性及光合作用对高温的响应

Response of Protective Enzyme Activity and Photosynthetic Characteristics of Fagopyrum dibotrys CV. Qianjin No.1 to High Temperature

以黔金荞麦1号为试验材料,采用室内盆栽方法,分别设置22℃、35℃和45℃共3个温度处理,研究高温胁迫对育成品种保护酶活性及光合作用的影响。结果表明,随高温胁迫强度的增加,黔金荞麦1号的丙二醛(MDA)含量、POD和CAT活性及非光化学荧光猝灭系数(NPQ)升高,SOD活性先升高后降低,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、水分利用效率(WUE)、PSⅡ的潜在活性(Fv/Fo)、实际光量子产量(Yield)和光化学猝灭系数(qP)降低。为适应高温胁迫,黔金荞麦1号品种能够增加POD和CAT等保护酶活性,降低高温对细胞膜的损伤;并通过减小Gs,增加NPQ,减少过剩激发能对光合系统的损伤,尽量维持较高的水分利用效率和光合生理功能。

The protective enzyme activity, gas exchange and chlorophy Ⅱ fluorescence of F. dibotrys CV. Qianjin No. 1 were investigated under high temperature stress （22 ℃, 35 ℃ and 45 ℃ ）. The results showed that with the increase of treatment temperature, the MDA content, activities of peroxidase （POD） and catalase （CAT） ,the non-photochemical fluorescence quenching （NPQ） had an increasing tendency. The superoxide dismutase（SOD） increased in the beginning and decreased at last. The net photosynthetic rate （Pn）, stomatal conductance （ Gs）, transpiration rate （ Tr）, water use efficiency （ WUE ）, PS Ⅱ potential activity （ Fv/Fo ）, PS Ⅱ actual photochemical quantum yield（yield） and PS Ⅱphotochemical fluorescence quenching （qv） had an decreasing tendency significantly. To adapt to the high temperature condition, the F. dibotrys CV. Qianjin No. 1 could increase the activities of peroxidase（POD） and catalase（CAT） to reduce the damage of cell membrane, and could decrease the Gs, increase NPQ, reduce the damage of excess excitation energy on photosynthetic systems, tried to maintain higher water use efficiency and photosynthetic physiological functions.