广西合果木生长及光合特性

Photosynthesis of Paramichelia baillonii under Drought Stress in Guangxi

在正常供水CK(土壤水分含量为最大田间持水量的80%,下同),轻度干旱胁迫P1(65%)、中度干旱胁迫P2(35%)、重度干旱胁迫P3(15%)4种处理方式下研究了合果木抗旱能力,对其叶片光合指标和叶绿素荧光值进行分析。结果表明,随着干旱强度的增强,合果木的光合作用能力不断降低,Pmax、Tr、Gs等光合指标不断下降。但Ci值在P2处理条件下达到最低,植物细胞获取CO2能力逐渐稳定,说明合果木的抗旱能力较弱;在对叶绿素荧光日变化值研究后发现,Fv/Fm、ΦPSII值会随着光照日变化自我恢复到一个稳定值,表明合果木在逆境条件下能够维持植物体内一定的光合作用,保证植物体自身的能量获取。

This paper mal water supply CK （ P2：35 %）, severe measures the drought tolerance soil moisture content of 80 % ）, drought stress （ P3 ： 15 % ）. of Paramichelia baillonii under four mild drought stress （P1 ： 65 % ） Measurements were conducted by drought scenarios ： nor- moderate drought stress analyzing photosynthesis and chlorophyll fluorescence values for Paramichelia baillonii leaves. The results showed that： as drought intensity rises, the photosynthetic capability of Paramichelia baillonii photosynthetic decreased, while Pmax, Tr, Gs and other photosynthetic indices also decreased. However, while the Ci value reached the minimum under P2 treat- ment, the ability for plant cells to sequester CO2 gradually stabilized, indicating that the drought tolerance of Pa- ramichelia baillonii is weak. Moreover, analysis of chlorophyll fluorescence found that Fv/Fm, Ф PSII values re- cover and stabilize with a change in illumination, demonstrating that Paramichelia baillonii is able to maintain a certain level of photosynthesis under stress conditions, and could ensure its energy gain