Responses of absorptive root and mycorrhizal colonization of Chinese fir (Cunninghamia lanceolata) to varied environmental conditions
Responses of absorptive root and mycorrhizal colonization of Chinese fir (Cunninghamia lanceolata) to varied environmental conditions
复制标题
DOI：
10.1007/s11258-022-01256-3
复制
发表时间：
2021-08
期刊：
影响因子：
1.7
通讯作者：
Y. Liao;H. Fan;Liang-qian Li;Xiaohua Wei;Huimin Wang;Honglang Duan;Wenfei Liu;Jiali Liu
中科院分区：
文献类型：
--
作者：
Y. Liao;H. Fan;Liang-qian Li;Xiaohua Wei;Huimin Wang;Honglang Duan;Wenfei Liu;Jiali Liu
根分枝和菌根共生是树木获取土壤资源的两种主要机制。了解这两种机制之间的关系及其对不同环境条件的响应对于预测根系觅食策略对环境变化的响应至关重要。以分布在中国亚热带不同环境条件下的11个杉木人工林为研究对象，研究了与养分取食相关的根尖性状（一级根与二级根分枝比、丛枝菌根定植）与其环境变量(年平均降水量（MAP）、年平均气温（MAT）、土壤C、土壤N、土壤P、根分枝比菌根共生对环境条件更敏感。杉木的分枝率和AM定植与几个环境变量显著相关。分支率与MAT呈显著正相关，与土壤C、N、pH呈显著负相关（P< 0.05），说明恶劣环境条件促进了吸收根分支。令我们惊讶的是，吸收根的AM定植对环境因素的敏感性不如分枝比。而AM在吸收根中的定殖量与土壤pH呈显著正相关（P< 0.1），说明土壤酸度对菌根共生有控制作用。分枝率与AM定植呈显著负相关（P< 0.05）。结果表明，环境条件对细根分枝及其菌根共生有显著调节作用，但控制变量不同。分枝率与AM定植呈负相关关系，说明环境因子对吸收根性状的调节方式不同。
Root branching and mycorrhizal symbioses are two major mechanisms for soil resource acquisition by trees. Understanding the relationship between these two mechanisms and their responses to varied environmental conditions is crucial for predicting the responses of foraging strategies of roots to environmental changes. This study was conducted in 11 Chinese fir (Cunninghamia lanceolata) plantations distributed in different environmental conditions in Subtropical China to assess the relationship between root tip traits related to nutrient foraging (branching ratio of 1st-order roots to 2nd-order roots, arbuscular mycorrhizal (AM) colonization) and their environmental variables, including mean annual precipitation (MAP), mean annual temperature (MAT), soil C, soil N, soil P, and soil pH. Root branching was more sensitive to environmental conditions than mycorrhizal symbioses. The branching ratio and AM colonization of Chinese fir were significantly related to several environmental variables. The branching ratios were positively correlated with MAT, but negatively correlated with soil C, soil N, and soil pH (P< 0.05), suggesting that harsh environmental conditions can promote absorptive root branching. To our surprise, the AM colonization of absorptive roots was not as sensitive to environmental factors as branching ratio. However, the AM colonization of absorptive roots was positively correlated with soil pH (P< 0.1), indicating that soil acidity controls mycorrhizal symbioses. Moreover, the branching ratio was significantly negatively correlated with AM colonization (P< 0.05). Our results confirmed that environmental conditions significantly regulate fine root branching and its mycorrhizal symbioses, but with different controlling variables. The negatively correlated relationship of branching ratio and AM colonization shows that environmental factors regulate absorptive root traits in different ways.