摘要
以耐热甜瓜品种红绿早脆和热敏感品种白玉香为材料,在人工气候箱内采用基质栽培法,研究了2,4-表油菜素内酯(EBR)处理对高温胁迫下甜瓜幼苗抗氧化酶活性和光合作用的影响.结果显示:EBR能有效促进高温胁迫下甜瓜幼苗的生长,增加保护酶活性,增强植株抗氧化能力,使脯氨酸和可溶性蛋白含量升高,丙二醛(MDA)含量下降,能有效缓解高温胁迫引起的膜脂过氧化伤害;同时,光合指标净光合速率(Pn)和气孔导度(Gs)升高,胞间CO2浓度(Ci)和蒸腾速率(Tr)下降;叶绿素荧光参数初始荧光(F0)下降,最大光化学效率(Fv/Fm)、光系统Ⅱ光能捕获效率(Fv′/Fm′)和实际光化学效率(ФPSⅡ)升高,且热敏感品种白玉香变化幅度大于耐热品种红绿早脆.研究结果说明,EBR有利于甜瓜幼苗在高温胁迫下抗氧化酶活性的提高和对光能的捕获与转换,促进了甜瓜幼苗的生长,降低高温胁迫对甜瓜幼苗的抑制作用,且对热敏感品种白玉香效果大于耐热品种红绿早脆.
The experiment was carried out by ‘Honglüzaocui’（heat-tolerant） and ‘Baiyuxiang’（heat-sensitive） in climate chambers and substrates to investigate the effects of 2,4-epibrassinolide（EBR） on melon seedlings for antioxidant enzyme activities and photosynthesis under high temperature stress.The results showed that EBR could increase melon-seedling growth,enhance leaf antioxidant enzyme activities and proline and soluble protein contents,reduce MDA content,suppress the membrane lipid peroxidation.EBR also raised leaf net photosynthetic rate and stomatal conductance,reduced transpiration rate,intercellular carbon dioxide concentration and F0,raised chlorophyll Fv/Fm,Fv′/Fm′,and ФPSⅡ under high temperature stress.Under high-temperature condition,we not only found that EBR caused enhancement in antioxidant enzyme activity and photosynthesis of two melon genotypes,but also found that the enhancement of heat-sensitive ‘Baiyuxiang’ was higher than that of heat-tolerant ‘Honglüzaocui’.Obviously,EBR was favorable for the seedlings to increase the growth and antioxidant enzyme activity,capture and converse solar energy,thus improving melon growth and abating the inhibitory effects of high temperature stress on melon.These findings suggest that ameliorative effect of EBR on melon seedlings with high temperature stress was effective,especially for heat-sensitive genotypes.
出处
《西北植物学报》
CAS
CSCD
北大核心
2011年第7期1347-1354,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
上海市科技兴农重点公关项目[沪农科攻字(2009)第2-1号]
上海市农科院青年科技发展基金[农青科技2010(5)号]
关键词
2
4-表油菜素内酯
甜瓜
高温胁迫
抗氧化酶活性
光合作用
2
4-epibrassinolide
melon
high temperature stress
antioxidant enzyme activity
photosynthesis
