Yang Rong, Li Shuming, Cai Xiaobu, Li Xiaolin, Christie Peter, Zhang Junling, Gai Jingping
College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
Tibet Agricultural and Animal Husbandry College, Tibet University, Linzhi, 860000, China.
Mycorrhiza. 2016 Oct;26(7):623-32. doi: 10.1007/s00572-016-0701-8. Epub 2016 Apr 19.
Plant adaptation to alpine ecosystems is not fully explained by plant physiological and morphological traits. Arbuscular mycorrhizal (AM) associations may be involved in mediating plant performance in response to environmental differences. Little is known, however, as to whether or not a close relationship exists between plant performance and arbuscular mycorrhizal fungus status across environmental gradients. We conducted a field investigation of the performance of six plant species and their associated AM fungi along higher and lower elevation gradients on Mount Segrila in Tibet. In most of our species, we observed higher shoot and inflorescence biomass production and a lower root-to-shoot ratio in the populations at those sites where the species was dominant (intermediate elevation sites) than in populations sampled at the limits of the distribution. The elevation pattern of root colonization differed with plant species on both gradients, and the extraradical hypha development of most species showed a unimodal pattern as did plant growth. The relationship between plant and fungus traits shows that AM fungus development generally matched host plant performance on the lower elevation gradient but not on the higher elevation gradient. This study provides evidence that plant distribution and productivity were significantly related to root and soil colonization by AM fungi, especially under less physically stressful conditions.
植物对高山生态系统的适应性不能完全由植物的生理和形态特征来解释。丛枝菌根（AM）共生关系可能参与调节植物对环境差异的响应表现。然而，关于在环境梯度上植物表现与丛枝菌根真菌状态之间是否存在密切关系，人们知之甚少。我们对西藏色季拉山高低海拔梯度上的六种植物及其相关的AM真菌的表现进行了实地调查。在我们研究的大多数物种中，我们观察到，在物种占优势的地点（中等海拔地点）的种群中，地上部分和花序生物量的产量较高，根冠比低于在分布范围边缘采样的种群。在两个梯度上，根定殖的海拔模式因植物物种而异，大多数物种的根外菌丝发育与植物生长一样呈现单峰模式。植物与真菌特征之间的关系表明，AM真菌的发育在低海拔梯度上通常与宿主植物的表现相匹配，但在高海拔梯度上则不然。这项研究提供了证据，表明植物分布和生产力与AM真菌对根和土壤的定殖显著相关，尤其是在物理压力较小的条件下。
