AM真菌对盐碱胁迫下杜梨幼苗生长与生理代谢的影响

Effects of arbuscular mycorrhiza fungi on the growth and physiological metabolism of Pyrus betulaefolia Bunge seedlings under saline-alkaline stress

【目的】探究接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对盐碱胁迫下杜梨幼苗生长与生理代谢及耐盐碱能力的影响,为杜梨菌根苗在盐碱地上植被构建中的应用提供理论依据。【方法】采用双因素试验设计,以1年生杜梨实生苗为材料,将幼苗分为AMF(摩西管柄囊霉,Funneliformis mosseae)接种和未接种两组,以Na2CO3同时进行盐碱处理(浓度梯度为0、100、200和300 mmol/L),并测定其生长与生理性状。【结果】接种AMF提高了盐碱胁迫下杜梨幼苗的株高生长量(△H)以及生物量积累,与未接种幼苗相比,接种组幼苗的△H和生物量在盐碱胁迫下降低的幅度显著减小。丛枝菌根在一定程度上降低了Na^+在杜梨根和叶的积累,在3个Na2CO3浓度处理下,接种组幼苗根中Na^+的含量分别比未接种组低10.8%、21.6%和19.4%,从而提高了接种组幼苗根和叶中K^+/Na^+、Ca^2+/Na^+、Mg^2+/Na^+的比值以维持较好的离子平衡状态。接种AMF可以提高盐碱胁迫下杜梨幼苗叶的叶绿素含量,降低脯氨酸和丙二醛在叶中的积累,表明接种AMF可以减轻盐碱胁迫对杜梨造成的离子毒害与过氧化伤害。【结论】AMF直接影响盐碱胁迫下杜梨幼苗生理代谢,提高其光合色素含量,维持其体内离子相对平衡,减少活性氧伤害,从而提高了杜梨幼苗的耐盐碱能力,促进其在盐碱胁迫下的生长。

【Objective】To provide a scientific guidance for the application of Pyrus betulaefolia Bunge rhizome seedlings in afforestation of saline-alkaline lands, the effects of arbuscular mycorrhizal fungi(AMF) on plant growth and physiological characteristics in P. betulaefolia Bunge seedlings under saline-alkaline stress were investigated. 【Method】A two-factor experimental design was conducted to compare the impacts of AMF inoculation and saline-alkaline stress on the growth and physiological metabolism on one-year-old P. betulaefolia Bunge seedlings. The seedlings were divided into two groups [AMF(Funneliformis mosseae) inoculated and non-inoculated] and were treated with Na2CO3(concentration gradient: 0, 100, 200 and 300 mmol/L) at the same time, and their growth and physiological characteristics were measured. 【Result】The AMF significantly increased plant height growth and biomass accumulation of P. betulaefolia Bunge seedlings under the Na2CO3 treatment. The decrease of △H and biomass under the salt-alkali stress was inhibited by AMF inoculation. AMF inoculation significantly affected the absorption and distribution of K+, Na+,Ca2+ and Mg2+ in P. betulaefolia Bunge. Na+ content in seedling roots of the inoculated was 10.8%, 21.6% and 19.4 lower than that of the non-inoculated under 3 different Na2CO3 concentrations, respectively. The K+/Na+, Ca2+/Na+ and Mg2+/Na+ ratios in the roots and leaves of seedlings inoculated with AMF were higher than those of the seedlings without inoculation because of the decline of Na+ absorption. Inoculation with AMF can reduce proline and malondialdehyde(MDA) content and increase the chlorophyll contents in seedling leaves, indicating that AMF can alleviate the oxidative damage and ion toxicity of saline-alkali stress on seedlings. 【Conclusion】It is conclude that AMF inoculation increased the content of photosynthetic pigment, maintained the relative ions balance in the plant and alleviate the oxidative stress, thus improving the salt-alkali tolerance and promoting the seedlings growth of P. betulaefolia Bunge under saline-alkaline stress.