摘要
为了探讨外源硅提高多年生黑麦草抗盐性的效应,采用水培试验,研究了外源硅对NaCl胁迫下多年生黑麦草幼苗活性氧代谢和光合作用的影响。结果表明,硅不仅能显著降低NaCl胁迫下多年生黑麦草幼苗根和叶片中丙二醛(MDA)和过氧化氢(H2O2)的含量及超氧阴离子(O2.-)产生速率,提高超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)的活性及谷胱甘肽(GSH)含量,还能提高NaCl胁迫下叶片的叶绿素含量、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),降低胞间CO2浓度(Ci)和叶绿素初始荧光(Fo),减缓NaCl胁迫导致的叶片PSII潜在光化学活性(Fv/Fo)、最大光化学效率(Fv/Fm)、光合电子传递量子效率(ΦPSII)、光化学狡灭系数(qP)和非光化学狡灭系数(NPQ)的下降,表明外源硅能提高盐胁迫下多年生黑麦草幼苗活性氧的清除能力,保护光合机构,改善光合功能,从而增强植株的耐盐性。
To investigate the effect of applying exogenous silicon to improve perennial ryegrass （Loliurn perenne L. ） salt resistance, the effects of exogenous silicon on the active oxygen metabolism and parameters of photosynthesis and chlorophyll fluorescence in perennial ryegrass seedlings under NaCI stress were studied by hydroponic experiments. The results showed that additional silicon in nutrient solution could not only significantly decrease the contents of malondialdehyde （MDA） and H2O2 and O2· - production rate in roots and leaves of perennial ryegrass seedlings under NaCl stress, increase the activities of superoxide dismutase （SOD）, catelase （CAT）, peroxidase （POD） and ascorbate peroxidase （APX） and the glutathione （GSH） content, but also significantly increased chlorophyll content, net photosynthetic rate （Pn）, stoma- tal conductance （Gs） and transpiration rate （Tr）, reduced intercellular carbon dioxide concentration （Ci） and minimal fluorescence （Fo） in perennial ryegrass seedling leaves under NaCl stress, and inhibited the decreases in PSII potential fluorescence efficiency （Fv/Fo）, PSII maximum fluorescence efficiency （Fv/ Fm）, actual photochemical efficiency of PSII （ΦPSII）, photochemical quenching （qP） and non--photochemical quenching （NPQ） caused by NaCI stress. The above results suggest that exogenous silicon could increase the ability of active oxygen scavenging in perennial ryegrass seedlings under NaCl stress, protect photosynthetic system and enhance photosynthesis, which elevated the salt tolerance of plants.
出处
《中国草地学报》
CSCD
2008年第5期25-31,共7页
Chinese Journal of Grassland
基金
甘肃省教育厅科研基金资助项目(JY0510-07)
关键词
多年生黑麦草
硅
盐胁迫
活性氧代谢
光合参数
Perennial ryegrass （Loliurn perenne L. ）
Silicon
Salt stress
Active oxygen metabolism
Photosynthetic characteristics
