低温胁迫下丛枝菌根真菌对玉米幼苗形态、生长和光合的影响

Effect of Arbuscular Mycorrhizal Fungus on Morphology,Growth and Photosynthetic Characteristics in Maize Seedlings under Low Temperature Stress

为了解丛枝菌根真菌对玉米抗寒性的作用及其机理,利用盆栽试验,研究了低温胁迫下丛枝菌根(AM)真菌接种处理对玉米幼苗形态、生长和光合特征的影响。研究显示,低温胁迫下,与非AM真菌接种处理玉米相比,接种玉米具有更大的叶片大小和更高的地上生物量。低温胁迫降低了玉米叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr),增加了叶片胞间CO2浓度(Ci)。接种丛枝菌根真菌的玉米Pn、Gs和Tr高于不接种植株,而Ci低于不接种植株。低温胁迫下,玉米叶片初始荧光(Fo)升高,而可变荧光(Fv)、最大荧光(Fm)、最大光化学效率(Fm/Fv)和潜在光化学效率(Fv/Fo)均下降。无论常温或低温,接种AM真菌玉米叶片Fm和Fv高于非接种植株,同时,接种真菌玉米的叶片Fm/Fv和Fv/Fo也均高于不接种植株。研究结果表明,低温能够对玉米幼苗的生长和光合生理造成严重伤害;低温胁迫下,接种AM真菌能够通过其对玉米植株的保护和促进作用改善玉米的生长,以及对叶片光合系统的保护作用提高玉米的光合能力,增强玉米幼苗的抗寒能力。

For understanding the effects and effect mechanisms of arbuscular mycorhizal（AM） fungus on low temperature tolerance of maize.The effect of arbuscular mycorhizal（AM） fungus inoculation on morphology,growth and photosynthetic characteristics of maize seedlings was studied in pot culture under low temperature stress.Study showed that under low temperature stress,compared with non AM-inoculated maize plants,AM-inoculated maize plants had larger leaf size and higher aboveground biomass.Low temperature stress decreased the photosynthetic rate（Pn）,stomatal conductance（Gs） and transpiration rate（Tr） of maize leaves,but increased the intercellular CO2concentration（Ci）.The Pn,Gs and Tr of AM-inoculated maize leaves were higher than those of non AM-inoculated plants,and the Ci of AM-inoculated maize leaves was lower than that of non AM-inoculated plants.Under low temperature stress,the primary fluorescence（Fo） was increased,while variable fluorescence（Fv）,maximal fluorescence（Fm）,maximum photochemical efficiency（Fv /Fm） and potential photochemical efficiency（Fv /Fo） were decreased.Without regard of temperature,compared with AM-inoculated maize plants,AM-inoculated plants had higher Fv,Fm,Fv / Fm and Fv / Fo.The results indicated that low temperature could induce serious damage of growth and photosynthetic physiology of maize seedling;AM inoculation could enhance low temperature tolerance of maize seedling by protective and facilitated effects on maize plants to promote its growth,and protective effect on photosyntheticsystem to improve its photosynthetic capacity.