中国东西部杨树人工林外生菌根形态及其分布特征

Ectomycorrhizal morphologies and their distribution characteristics in artificial Populus forests of eastern and western China

外生菌根由真菌与植物根系建立共生关系而形成,其形态是表征植物环境适应性的重要性状。为揭示杨树外生菌根分布特征及其探索类型调控杨树环境适应能力,从中国东西部9个主要的杨树栽培区共采集77份杨树根系样品,分析了外生菌根形态特征及不同探索类型的地理分布。所采集样品中共观察到35种杨树外生菌根形态,归属于紧密接触型、短距离养分获取型和中距离养分获取型等三种探索类型。中国东部和西部地区的杨树外生菌根形态有显著差异,西部地区杨树外生菌根形态数量和多样性均显著高于东部。东部地区杨树外生菌根主要为紧密接触型,西部地区杨树外生菌根主要为短距离养分获取型,中距离养分获取型菌根仅在西部地区观察到。年平均降水量是影响杨树外生菌根探索类型分布的主要环境因子,紧密接触型菌根的定殖与年平均降水量显著呈正相关,而短、中距离养分获取型菌根的定殖与年平均降水量条件呈显著负相关。其次,土壤理化性质也影响着杨树的外生菌根分布,紧密接触型菌根与土壤pH显著负相关,与铵态氮和全钾显著正相关,而短、中距离养分获取型菌根与土壤pH显著正相关,与铵态氮和全钾显著负相关。在气候变暖和土壤质量退化的全球背景下,研究结果为研究杨树外生菌根生态功能及其对环境变化的响应机制提供科学依据。

Ectomycorrhizal are formed through a symbiotic relationship between fungi and plant roots,and their morphology is an important trait that characterizes the plant′s adaptability to the environment.To reveal the distributional characteristics of Populus ectomycorrhizas and their different exploration types of ectomycorrhizas regulating the environmental adaptability of Populus trees,this study collected 77 root samples from nine major Populus cultivation areas in eastern and western China.The morphological features of ectomycorrhizas and the distribution of different exploration types were then analyzed.A total of 35 morphological types of Populus ectomycorrhizas were observed in the collected samples,which were classified into three exploration types:contact exploration type,short-distance exploration type,and medium-distance exploration type.There were significant differences in the ectomycorrhizal morphologies between eastern and western China,with the western region having a higher number and morphological diversity of ectomycorrhizal types compared to that in the eastern region.In the eastern region,Populus ectomycorrhizas were predominantly contact exploration type,while in the western region,they were mainly short-distance exploration type,with medium-distance exploration type observed only in the western region.Annual average precipitation was identified as the primary environmental factor affecting the distribution of Populus ectomycorrhizal morphologies,with the colonization of contact exploration type mycorrhizas showing a significant positive correlation with annual average precipitation,whereas the colonization of short-distance exploration type and medium-distance exploration type showed a significant negative correlation with precipitation conditions.Secondly,the physical and chemical properties of the soil also affect the distribution of ectomycorrhizas on poplar trees.The contact exploration type of mycorrhizae exhibited a significant negative correlation with soil pH and a significant positive correlation with ammonium nitrogen and total potassium.In contrast,short-distance exploration type and medium-distance exploration type of mycorrhizae showed a significant positive correlation with soil pH and a significant negative correlation with ammonium nitrogen and total potassium.Against the global background of climate warming and soil quality degradation,the findings have offered a scientific foundation for future research into the ecological functions of poplar ectomycorrhizal and their adaptive mechanisms to environmental changes.