摘要
以白三叶品种‘Pixie’和‘MAG’为供试材料,用15%PEG(聚乙二醇-6000)模拟干旱胁迫,通过测定叶片外观表现、相对含水量(RWC)、电导率(EL)、丙二醛(MDA)、内源激素水平、相对生长速率(RGR)、渗透调节物质含量以及光合参数,探讨两品种白三叶的抗旱性差异及其生理机制。结果表明:干旱胁迫下,两品种植株叶片萎蔫程度逐步加重、RWC不断降低,而EL和MDA则持续升高,与‘MAG’相比,‘Pixie’的萎蔫程度较轻,RWC较高,EL和MAD较低。干旱胁迫使两品种的叶绿素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(gs)、水分利用效率(WUE)显著降低,而胞间CO_2浓度(Ci)逐渐升高,但‘Pixie’比‘MAG’维持了较高的叶绿素含量、Pn和WUE,以及较低的gs、Tr和Ci。与此同时,两品种叶片中ABA含量显著增加,IAA、GA以RGR则显著降低,而‘Pixie’维持了显著高的ABA和GA,以及显著低的IAA和RGR。此外,‘Pixie’比‘MAG’有显著高的脯氨酸和可溶性糖含量以及显著低的渗透势和水势。综上所述,‘Pixie’的抗旱性强于‘MAG’。
Two white clover cuhivars ‘ Pixie＇ and including phenotypes, relative water content （RWC） ‘MAG＇ were used to analyze physiological changes , relative leakage of electrolyte （EL）, malondialdehyde （MDA）, endogenous hormones, relative growth rate（RGR）, osmotic adjustment, and photosynthet ic parameters under drought stress induced by 15% PEG-600 nutrient solution. The results showed that water deficit aggravated leaves wilt and reduced RWC gradually, and increased EL and the content of MDA constantly, However the phenotype of ‘ Pixie＇ was better than that of ‘ MAG＇, and ‘ Pixie＇ maintained significantly higher RWC but lower EL and MDA in response to water deficit. Drought stress obviously in- duced decreases in chlorophyll contents, net photosynthetic rate （Pn）, transpiration rate （Tr）, stomatal conductance （sc） and water use efficiency （WUE）, hut increase in intercellular CO2 concentration （Ci） in both cuhivars. Differently, ‘Pixie＇ exhibited higher chlorophyll contents, Pn, and WUE as well as lower gs, Tr, and Ci in leaves as compared to ‘MAG＇. In addition, drought stress increased the ABA content, and decreased IAA and GA content in both cuhivars. ‘Pixie＇ had higher ABA and GA content, but lower IAA content than ‘MAG＇ under drought stress. The proline and soluble sugar contents were significant higher, while osmotic and water potential were significantly lower in leaves of ＇Pixie＇ than that of ‘MAG＇ in response to drought stress. The results suggested that drought tolerance of ‘Pixie＇ was stronger than that of ‘MAG＇.
作者
李亚萍
谢欢
雍斌
彭燕
LI YA-Ping XIE Huan YONG Bin PENG Yan(College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China)
出处
《中国草地学报》
CSCD
北大核心
2017年第1期63-70,共8页
Chinese Journal of Grassland
基金
自然科学基金(31372371)
国家现代牧草产业技术体系(CARS-35)
关键词
干旱胁迫
激素含量
渗透调节
光合特性
白三叶
Drought stress
Phytohormone
Osmotic adjustment
Photosynthesis
White clover
