Abstract:

On the basis of analyzing natural variation of water use efficiency in Chinese germplasm of Zoysia Willd., High water use efficiency zoysia grass material Z110 and low water use efficiency Zoysia grass material Z132 were used as test plant materials, and to study the effects of drought stress on their chlorophyll fluorescence and key photosynthetic enzyme activities. The results showed that chlorophyll initial fluorescence(Fo) and the non-photochemical quenching(qN) increased gradually, maximal fluorescence(Fm), effective quantum yield of PSⅡ photochemistry (Yield), apparent electron transport rate (ETR), the photochemical quenching (qP), phosphoenolpyruvic acid (PEP) activity and Ribulose bishosphate (RuBP) activity reduced gradually. Other parameters of Z110 were larger than those of Z132 besides Fo during drought stress. It suggested that drought stress had larger effect on material Z132, and material Z110 had a stronger adaptability to drought stress than the Z132.

Key words: Drought stress, Zoysia japonica, Chlorophyll Fluorescence, Key photosynthetic enzyme activities

摘要：

在对中国结缕草属（Zoysia Willd.）植物53份种源水分利用效率评价的基础上，以高水分利用效率种源Z110和低水分利用效率种源Z132作为试验材料，对其干旱胁迫过程中叶绿素荧光特征、光合关键酶核酮糖二磷酸（RuBP）羧化酶和磷酸烯醇式丙酮酸（PEP）羧化酶的活性进行了研究。结果表明，在干旱胁迫过程中，两份结缕草种源的叶绿素初始荧光（Fo）、非光化学猝灭系数（qN）逐渐增加；叶绿素最大荧光（Fm），PSⅡ实际光化学效率Yield，叶片表观光合电子传递速率ETR，PSⅡ光化学猝灭系数（qP），RuBP羧化酶和PEP羧化酶活性逐渐降低。在干旱胁迫过程中，除种源Z110叶绿素Fo小于Z132的叶绿素Fo外，其他参数均大于Z132，说明干旱胁迫对Z132的光合作用影响较大，Z110对干旱胁迫表现出较强的的适应能力。

关键词: 干旱胁迫, 结缕草, 叶绿素荧光, 光合关键酶