摘要
以‘津研四号’黄瓜品种为试材，研究了叶面喷施不同浓度硅（Si）（0、1、2、3、4、5mmol·L^-1）对连作黄瓜幼苗生长、光合特性和抗氧化酶活性的影响．结果表明：在一定浓度（1～3mmol·L^-1 Si）范围内，施si可降低幼苗叶片电解质渗漏率（EL）和丙二醛（MDA）含量；提高叶绿素a（Chla）、叶绿素b（Chlb）、类胡萝卜素（Car）和总叶绿素含量，叶片净光合速率（Pn）升高；超氧化物歧化酶（SOD）、过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）活性均有所提高；黄瓜幼苗株高、茎粗、叶面积及干物质积累量增加．随施Si浓度的进一步增加（4～5mmol·L^-1），叶片中EL和MDA含量升高，但仍低于对照；抗氧化酶活性和光合作用下降，幼苗生长受到显著抑制．说明外源si可通过提高黄瓜幼苗叶片抗氧化酶活性来降低膜脂过氧化，通过增加光合作用来提高黄瓜幼苗长势，进而增强对连作障碍的抗性．以2mmol·L^-1Si处理效果最好．
The effects of spraying exogenous silicon growth, photosynthetic characteristics and activity （Si） （0, 1,2, 3,4 and 5 mmol · L^-1） on the of antioxidant enzymes in continuous-cropped ‘Jinyan NO. 4＇ cucumber seedlings were studied. The results showed that with the application of 1-3 mmol · L^-1 Si, electrolyte leakage （EL） and malondialdehyde （MDA） content in leaves were significantly decreased, while the contents of chlorophyll a （Chl a）, chlorophyll b （Chl b）, caro- tenoids （Car）, chlorophyll （a＋b） and photosynthetic rate （Pn） in leaves were significantly im- proved, the activities of superoxidase （ SOD）, peroxidase （ POD）, catalase （CAT） and ascorbic acid peroxidase （APX） were significantly increased, and the plant height, stem diameter and dry mass accumulation of cucumber seedlings were promoted. Compared with the low Si concentrations, excessive Si （4-5 mmol · L^-1 ） resulted in higher EL and MDA, which were still lower than that in control, decreased the antioxidant enzymes activity and photosynthesis, and inhibited the growth of cucumber seedlings. These findings indicated that exogenous Si could enhance the capacity of sca- venging active oxygen species and improve photosynthesis, protect cucumber seedlings from the lipid peroxidation, and increase the resistance to continuous-cropped cucumber obstacle. The opti-mal silicon concentration was 2 mmol · L^-1.
出处
《应用生态学报》
CAS
CSCD
北大核心
2014年第6期1733-1738,共6页
Chinese Journal of Applied Ecology
基金
"十二五"国家科技支撑计划项目(2011BAD12B04)
国家自然科学基金项目(31372060)
现代农业产业技术体系专项资金项目(CARS-25-D)
山东省现代农业产业技术体系建设专项(SDAIT-02-022-08)资助
关键词
硅
连作
黄瓜
光合特性
抗氧化酶
silicon
continuous cropping
cucumber
photosynthetic characteristics
antioxidantenzymes.
