外生菌根提高板栗苗木抗旱性能及其机理的研究

A Study on Effect of Ectomycorrhizae on Promoting Castanea mollissima Resistance to Drought and Its Mechanism

苗木菌根化能够提高对干旱胁迫的抵御能力。本试验证明菌根技术具有提高板栗苗木抗干旱性能的作用 :提高苗木束缚水含量 12 .0 8%～ 57.4 9% ;在干旱胁迫下叶片推迟 2 4～ 4 3.2 h出现萎蔫 ,重新复水后提前 4 .8～ 2 8.8h恢复正常 ,萎蔫系数降低 2 1.95%～ 58.0 4 % ,有效光合强度提高 3.84 %～ 2 30 .72 %。菌根化提高宿主耐旱力的机理部分在于菌根化能影响到植物体内部的组织结构变化 :叶肉质化程度提高 0 .0 9%～ 7.88% ,比叶面积增大 2 .6 7%～ 18.83%。这种组织结构上的变化进而影响到生理特性的变化 :叶保水力增大 ,水分饱和亏缺降低 5.59%～ 2 9.6 1%。叶肉质化程度、比叶面积和叶保水力首次应用在菌根研究中。另外 ,正常情况下高于对照的蒸腾速率 (用气孔导度及气孔阻力反映 )在干旱胁迫下降为低于对照的水平。同时接种菌根菌能提高苗木在正常情况下的水分有效利用率 (7.89%～ 79.78% )及干旱胁迫下的水分有效利用率 (4 .78%～ 6 3.89% )。游离脯氨酸含量在对照体内迅速增加 (50 .54% ) ,表明此时对照处于缺水状态 ,而菌根化苗仍未或只是轻微地感受到干旱胁迫。综合以上多种因素 ,美味牛肝菌。

Mycorrhizal biotechnology can raise the resistance to drought of Castanea mollissima seedlings:increase the content of bound water in leaf by 12.08%～57.49%;under the condition of water stress,delay the time of leaf wilting up to 1～1.8 days,advance recovery time from wilting up to 0.2～1.2 days after irrigation,decrease wilting coefficient by 21.95% ～58.04%,amplify net photosynthesis rate by 3.84%～230.72%.The study demonstrates that inoculation can change the organic structure:increase the degree of leaf succulence by 0.09%～7.88%,specific leaf area by 2.67%～18.83%.It influences the physiological characters:raise leaf water holding ability and decrease water saturation deficit by 3.54%～29.61%.Degree of leaf succulence,specific leaf area and leaf water holding ability were adopted in the research of mycorrhizae firstly.Additionally,transpiration rate (expressing with stomatal resistance and conductance) of inoculating seedlings is lower than the control group under water stress while it is higher under normal condition.At the same time,inoculation improve the water use efficiency of Castanea mollissima ,i.e 7.89%～79.78% under water stress,4.78%～63.89% under normal condition.Free proline content increases rapidly in control group seedlings 50.54%.It does indicate that the control group is deficient of water supply,but the inoculated seedlings still not or little feels water stress.In sum, Boletus edulis,Xerocomus chrysenteron and Cortinarius sublanatus are good ECM fungi of Castanea mollissima.