喷钙对干旱胁迫下葡萄光合作用及叶绿素荧光参数的影响

目的]研究外源钙对干旱胁迫下葡萄叶片光合及荧光的影响,探讨钙在干旱胁迫下对叶片光系统的保护机制。方法]以两年生红地球葡萄为试材,设置干旱、干旱喷钙、CK、CK喷钙4个处理,测定叶片光合及叶绿素荧光参数。结果]喷施外源钙处理减缓了干旱胁迫下叶片叶绿素的降解,保持了较高的SPAD值;显著提高了叶片的净光合速率(Pn)等光合参数,维持了干旱胁迫下光系统Ⅱ(PSⅡ)较高的活性,光化学猝灭系数(q P)、PSⅡ的天线转换效率(Fv’/Fm’)、光系统Ⅱ最大光化学效率(Fv/Fm)、电子传递速率(ETR)均显著高于对照,初始荧光(Fo)显著小于对照。外源钙通过调节气孔开闭,保持较高的气孔导度;减缓叶绿素的降解,增加光合电子传递,维持较高的ФPSⅡ,进而有效缓解了干旱对葡萄叶片光合作用的抑制,维护了干旱胁迫下光系统Ⅱ的活性。结论]该研究可为提高葡萄的抗旱能力提供参考。

Effects of Calcium Spray on Photosynthesis and Chlorophyll Fluorescence of Grape under Drought Stress

Objective] To investigate the effect of exogenous calcium on photosynthesis and chlorophyll fluorescence of table grape,as well as the photoprotective function of calcium on photosystem under water stress . Method] An experiment was conducted on two-year-old potted table grape (Vitis vinifera L.cv.Red Globe) with four treatments,well watered with water foliar spray,well watered with calcium foliar spray,water stressed with water foliar spray ,water stressed with calcium foliar spray .Photosynthesis and chlorophyll fluorescence of leaves were determined . Result ] Calcium foliar spray retarded the degradation of chlorophyll by sustained a relatively high SPAD,significantly improved net photosyn-thesis rate (Pn),sustained a high activity of photosystemⅡwith higher photochemical quenching (qP),antenna efficiency of PSⅡ(Fv'/Fm'), maximum photochemical efficiency of PSⅡ(Fv/Fm),electron transport rate (ETR),and less initial fluorescence (Fo) than water foliar spray. Exogenetic calcium helped sustain the activity of PSⅡby sustaining high stomatal conductance,reducing chlorophyll degradation,increasing the photosynthetic electron transport,and sustaining high ФPSⅡ.Conclusion]The research can give reference for improving drought-resistant ability of grape.