水分及混合接菌对杜鹃光合特性的影响

Effects of Different Water and Mixed Inoculation on the Photosynthetic Characteristics of Rhododendron simsii Planch

目的:探索杜鹃苗对不同水分梯度及混合接菌的光合响应机制。方法:以1年生杜鹃为研究对象,采用D(四种杜鹃花类菌根真菌混合接菌)、DM(四种杜鹃花类菌根真菌和一种马尾松外生菌混合接菌)、CK(不接菌,对照)3种接菌组合与不同水分梯度即轻度水湿W1(85%~95%)、正常水分W(75%~80%)、轻度干旱T1(60%~65%)、中度干旱T2(50%~45%)和重度干旱T3(35%~40%),研究菌根真菌与水分对杜鹃苗光合特性的影响。结果:混合接菌处理能提高杜鹃叶片叶绿素含量、光合特征参数及叶绿素荧光参数。水分胁迫环境下混合接菌处理能促进杜鹃生长,提高杜鹃叶绿素含量、使接菌处理杜鹃苗的净光合速率、蒸腾速率、气孔导度的降幅小于CK处理。结论:在水分胁迫环境下接种DM相较于D和CK,最能显著提高杜鹃苗的光合能力,且以中度干旱条件下最为明显。

Objective:To explore the photosynthetic response mechanism of Rhododendron simsii Planch seedlings to different water gradients and mixed inoculation.Method:One-year-old R.simsii Planch was used as the research object,using D(mixed inoculation of four rhododendron mycorrhizal fungi),DM(mixed inoculation of four rhododendron mycorrhizal fungi and one masson pine ectophyte),CK(No in⁃oculation,control)3 kinds of inoculation combinations and different moisture gradients,namely mild wa⁃ter wet W1(85%-95%),normal moisture W(75%-80%)mild drought T1(60%-65%),moderate drought T2(50%-45%)and severe drought T3(35%-40%),to study the effects of mycorrhizal fungi and water on the photosynthetic characteristics of R.simsii Planch seedlings.Results:The results showed that the mixed inoculation treatment could increase the chlorophyll content,photosynthetic characteristic parameters and chlorophyll fluorescence parameters of R.simsii Planch Mixed inoculation treatment un⁃der water stress environment could promote the growth of R.simsii Planch,increase the chlorophyll con⁃tent of R.simsii Planch,and make the net photosynthetic rate,transpiration rate and stoma conductance of R.simsii Planch inoculated treatment less than CK treatment.Conclusion:Compared with D and CK,inoculation of DM under water stress environment could significantly increase the photosynthetic capacity of R.simsii Planch seedlings,and it was most obvious under T2 water conditions.