【目的】探究接种丛枝菌根(arbuscular mycorrhizal,AM)真菌对盐胁迫下文冠果(Xanthoceras sorbifolium)生长、生理代谢及耐盐能力的影响。【方法】以摩西斗管囊霉(Funneliformis mosseae)为供试菌种,选用1年生文冠果实生苗进行盆栽试验,进行接种与不接种处理,分别设置5种不同浓度(0、80、160、240、320 mmol/L)的NaCl胁迫,胁迫结束后测定文冠果幼苗生物量、侵染特性及生理指标。【结果】①盐胁迫下,接种AM真菌提高了文冠果地上、地下生物量;随着盐浓度的增加,其根系菌根侵染率显著降低。②接种AM真菌增加了文冠果叶片可溶性蛋白、脯氨酸、还原型谷胱甘肽(GSH)和还原型抗坏血酸(AsA)含量,增强了超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,而相对电导率和丙二醛(MDA)含量明显降低。③双因素方差分析显示时间和浓度对接种与未接种AM真菌处理下的文冠果叶片MDA、脯氨酸、可溶性蛋白和AsA含量有极显著交互效应(P <0.01);文冠果接种组对320 mmol/L盐胁迫的抗性最好。【结论】AM真菌可提高盐胁迫下文冠果渗透调节能力,增强抗氧化酶活性,增加抗氧化物含量,表明AM真菌能够提升文冠果耐盐能力,促进植物生长。

【Objective】An investigation on the effects of arbuscular mycorrhizal (AM) fungi inoculation on the growth, physiological metabolism, and salt tolerance of Xanthoceras sorbifolium under salt stress was conducted.【Method】In this study, Funneliformis mosseae was used to infect seedlings and the pot experiment was carried out using one-year-old X. sorbifolium seedlings. We applied different concentrations of NaCl stress (0, 80, 160, 240, and 320 mmol/L). After the stress period, the biomass, colonization characteristics, and physiological indicators of the X. sorbifolium seedlings were measured.【Result】(1)The aboveground and underground biomasses of X. sorbifolium seedlings were enhanced significantly by AM symbiosis upon exposure to salinity. Increasing salinity significantly caused a decrease in the mycorrhizal colonization rate.(2)AM fungi inoculation significantly improved the contents of soluble protein, proline, glutathione(GSH), and ascorbic acid (AsA), and resulted in an increasement in the activities of superoxide dismutase (SOD) and peroxidase (POD), yet a reduction in the relative conductivity and accumulation of malondialdehyde (MDA).(3)Furthermore, two-way analysis of variance(Two-way ANOVA)demonstrated that the duration and concentration were interactively and significantly affecting correlated with the content of MDA, proline, soluble protein, and AsA (P<0.01). Based on principal component analysis(PCA), it was found that the inoculation group had the most profound impact on the physiological characteristics of X. sorbifolium at 320 mmol/L NaCl treatment.【Conclusion】This study found that inoculation with AM fungi may advance osmotic mediation ability, significantly improve the activities of antioxidant enzymes and the contents of antioxidants, and enhance the salt tolerance of plants and eventually promote the growth of X. sorbifolium seedlings under different salt concentrations.