亚热带典型树种根毛特征及其与共生真菌的关系  

Relationships between root hairs and mycorrhizal fungi across typical subtropical tree species

作　　者：张慧[1,2,3] 曾文静[1,2] 龚新桃 马泽清 ZHANG Hui;ZENG Wen-Jing;GONG Xin-Tao;MA Ze-Qing(Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Qianyanzhou Subtropical Forest Ecological Research Station,Chinese Academy of Sciences,Ji’an,Jiangxi 343700,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [2]中国科学院千烟洲亚热带森林生态系统观测研究站,江西吉安343700 [3]中国科学院大学资源与环境学院,北京100049 [4]北京林业大学水土保持学院,北京100083

出　　处：《植物生态学报》2023年第1期88-100,共13页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31822010);国家重点研发计划(2020YFA0608102)。

摘　　要：根毛和共生真菌增加了吸收面积,提高了植物获取磷等土壤资源的能力。由于野外原位观测根表微观结构较为困难,吸收细根、根毛、共生真菌如何相互作用并适应土壤资源供应,缺乏相应的数据和理论。该研究以受磷限制的亚热带森林为对象,选取了21种典型树种,定量了根毛存在情况、属性变异,分析了根毛形态特征与共生真菌侵染率、吸收细根功能属性之间的关系,探讨了根表结构对低磷土壤的响应和适应格局。结果表明:1)在亚热带森林根毛不是普遍存在的,21个树种中仅发现7个树种存有根毛,4个为丛枝菌根(AM)树种,3个为外生菌根(ECM)树种。其中,马尾松(Pinus massoniana)根毛出现率最高,为86%;2)菌根类型是理解根-根毛-共生真菌关系的关键,AM树种根毛密度与共生真菌侵染率正相关,但ECM树种根毛直径与共生真菌侵染率负相关;3)AM树种根毛长度和根毛直径、ECM树种根毛出现率与土壤有效磷含量呈负相关关系。该研究揭示了不同菌根类型树种根毛-共生真菌-根属性的格局及相互作用,为精细理解养分获取策略奠定了基础。Aims Root hairs and mycorrhizal fungi,by increasing absorbing area of plant roots,promote ability of plants in acquiring soil resources such as phosphorus(P).The combination of absorptive roots,root hairs,and mycorrhizal fungi differs among distinct plant species,resulting in variations in acquisition of soil resources.At present,in situ quantifications of microstructures on the surface of roots is difficult,and relationships among absorptive roots,root hairs,and mycorrhizal fungi underlying the adaptation of soil P gradient in different woody plants remain largely unknown.Methods We investigated 21 tree species in a subtropical forest and examined the existence of root hairs.We quantified the variation of root hair characteristics and analyzed the relationships between root hairs,mycorrhizal colonization rate,root traits along with soil P availability.Important findings 1)Root hairs did not commonly exist in 21 subtropical tree species.We only observed root hairs in seven species,including four arbuscular mycorrhizal(AM)trees and three ectomycorrhizal(ECM)trees.Root hair occurrence rate was highest in Pinus massoniana(86%).2)Mycorrhizal type is key to understanding the relationships between root hairs and mycorrhizal fungi.Root hair density was significantly positively correlated with mycorrhizal fungi colonization rate in AM trees.In contrast,in ECM trees,root hair diameter was significantly negatively correlated with mycorrhizal fungi colonization rate.3)Root hair length and diameter were negatively correlated with soil available P content in AM trees,while root hair occurrence rate decreased with the soil available P content in ECM trees.Our results improve the understanding of root hairs and their interaction with other plant traits in natural forest stands,which lay the foundation for better predictions of nutrient acquisition strategies.

关 键 词：根毛出现率 根毛长度 根毛密度 根毛直径 菌根真菌侵染率 土壤有效磷 

分 类 号：Q948[生物学—植物学]