【摘要】 为了探讨外源葡萄糖对盐胁迫下山楂叶片的缓解效应,采用光合和叶绿素荧光技术,研究了葡萄糖对盐胁迫下山楂幼苗叶片光合与叶绿素荧光特性及细胞保护酶活性的影响。结果表明:葡萄糖能减轻因盐胁迫造成的叶片光合机构的破坏程度,提高叶绿素含量、净光合速率(Pn)及气孔导度(Gs),降低胞间CO2浓度(Ci),提高PSⅡ的最大光化学效率(Fv/Fm),PSⅡ潜在光化学效率(Fv/Fo),反应中心吸收的光能用于电子传递的量子产额(ΦEo)及以吸收光能为基础的光合性能指数(PIABS)。各浓度外源葡萄糖处理Pn、Fv/Fm及PIABS值比单一盐胁迫处理分别高3.4%～59.8%、5.4%～18.2%和5.6%～78.4%,表明外源葡萄糖提高了盐胁迫下山楂叶片光能利用率及光系统Ⅱ的光化学效率。同时,外源葡萄糖还能够显著提高其叶片内SOD和POD的活性,减少MDA的含量。5.0mmol.L-1外源葡萄糖处理叶片内SOD和POD活性比单一盐胁迫植株分别高21.1%和15.3%,而MDA的含量降低30.1%。更多还原

【Abstract】 For investigation on the alleviating effects of exogenous glucose on the leaves of hawthorn under salt stress,the effects of exogenous glucose on the photosynthesis and chlorophyll fluorescence characteristics as well as the activity of related cytoprotection enzymes of hawthorn under salt stress were studied.The results indicated that glucose could alleviate the damage of leaf photosynthetic structure caused by salt stress,increase the net photosynthetic rate(Pn) and stomatal conductance(Gs),decrease the intercellular CO2 concentration(Ci),and increase the maximum photochemical efficiency of PS Ⅱ(Fv/Fm),the potential quantum yield of PSII(Fv/Fo),the probability that an absorbed photon would move an electron into the electron transport chain beyond QA-(ΦEo) as well as the performance index on absorption basis(PIABS).The value of Pn,Fv/Fm and PIABS in exogenous glucose treatments increased by 3.4%-59.8%,5.4%-18.2% and 5.6%-78.4% compared to the salt stress treatment,respectively,which indicated that exogenous glucose could increase light energy utilization efficiency and the photosynthetic efficiency of PS Ⅱ of hawthorn seedlings.Meanwhile,exogenous glucose could also significantly increase the activities of SOD and POD in the leaves,reduce MDA content.The SOD and POD activities in 5.0 mmol.L-1 glucose treatment were about 21.1% and 15.3% higher than those under salt stress treatment,and the MDA content was about 30.1% lower.更多还原