摘要
[目的]探讨利用共生微生物提升重要生态树种木荷应对酸性红壤区低磷胁迫环境能力的可能。[方法]从木荷的根、茎、叶组织中分离并筛选出4株(根:MG37、MG42;叶:MY63、MY72)溶解铁磷效果较好的内生真菌,分析其解磷机理并采用盆栽实验明晰不同磷胁迫条件下(16、8、4、0 mg·kg^(−1))菌株对木荷幼苗养分吸收、酸性磷酸酶活性以及生长指标的影响。[结果]筛选出的4种解磷菌主要通过分泌有机酸溶解无效磷,菌液pH值与可溶性磷含量呈极显著负相关;所有菌株处理均可显著促进幼苗高生长,胁迫条件下MY72与MG37菌株处理的苗高、地径、生物量增色显著提高;MY72菌株处理的木荷幼苗在中度胁迫下有机碳含量和碳氮比最高,MG37菌株可显著提高幼苗在重度胁迫下的全磷含量,地上和地下分别增长84%和51%;4种供磷条件下,MG37菌株均可显著提高幼苗叶片酸性磷酸酶活性,在重度胁迫下MY72菌株处理的根际土壤酸性磷酸酶活性增长26%。[结论]4种内生真菌通过分泌有机酸溶解难溶性铁磷且在缓解低磷胁迫对木荷生长的抑制中具有积极作用,其中MG37和MY72菌株促生效果最好,具有潜在应用价值。
[Objective]The study aimed to investigate the potential of employing symbiotic microorganisms in enhancing phosphorus-deficiency resilience of Schima superba,an ecologically critical tree species,in acidic red soil ecosystems.[Methods]From the root,stem,and leaf tissues of S.superba,four endophytic fungi(MG37 and MG42 isolated from roots;MY63 and MY72 isolated from leaves)with potent iron-phosphate solubilizing capabilities were isolated and screened.Their phosphate-solubilizing mechanisms were analyzed,and pot experiments were subsequently conducted to examine the impact of these strains on nutrient absorption,acid phosphatase activity,and growth indicators of S.superba seedlings under various phosphorus stress conditions(16,8,4,and 0 mg·kg^(−1)).[Results]The four screened phosphate-solubilizing fungi primarily solubilize unavailable phosphorus through the secretion of organic acids,exhibited a highly significant negative correlation between the pH of the fungal suspension and the soluble phosphorus content.All strain treatments significantly promoted the growth in seedling height.Under stress conditions,MY72 and MG37 strain treatments resulted in significantly greater seedling height,ground diameter,and biomass.Seedlings treated with the MY72 strain exhibited the highest organic carbon content and carbon-to-nitrogen ratio under moderate stress conditions.Conversely,the MG37 strain significantly increased the total phosphorus content of seedlings under severe stress,with respective increases of 84%and 51%in the overground and underground parts.Across all four phosphorus supply conditions,the MG37 strain significantly enhanced the acid phosphatase activity in seedling leaves.Under severe stress conditions,the acid phosphatase activity in the rhizosphere soil of seedlings treated with the MY72 strain increased significantly by 26%.[Conclusion]The four endophytic fungi solubilize insoluble iron-phosphate through the secretion of organic acids and play a pivotal role in mitigating the inhibitory effects of low phosphorus stress on the growth of S.superba.MG37 and MY72 strains exhibit the most promising growth-promoting effects and hold significant potential for application.
作者
刘浩蓝
徐乾乐
熊佳玉
谯晓阳
徐欢
吴承祯
李键
LIU Hao-lan;XU Qian-le;XIONG Jia-yu;Qiao Xiao-yang;XU Huan;WU Cheng-zhen;LI Jian(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002,China;The Higher Educational Key Laboratory for Forest Ecosystem Process and Management of Fujian Province,Fujian Agriculture and Forestry University;College of Ecology and Resource Engineering,Wuyi University,Nanping 354300,China)
出处
《林业科学研究》
北大核心
2025年第4期64-75,共12页
Forest Research
基金
国家自然科学基金(32071753)。
关键词
低磷胁迫
木荷
内生真菌
解磷
促生
low phosphorus stress
Schima superba
endophytic fungi
phosphate solubilization
promoting effect.
