干旱条件下接种AM真菌对小马鞍羊蹄甲幼苗根系的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 干旱条件下接种AM真菌对小马鞍羊蹄甲幼苗根系的影响 DOI: 10.5846/stxb201601280209 作者: 作者单位: 中国科学院生态环境研究中心,中国科学院生态环境研究中心,中国科学院生态环境研究中心 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31170581） Inoculation with arbuscular mycorrhizal fungi enhances the root system of Bauhinia faberi var. microphylla seedlings under drought stress conditions Author: Affiliation: Research center for Eco-Environmental Sciences,Chinese Academy of Sciences,Research center for Eco-Environmental Sciences,Chinese Academy of Sciences,Research center for Eco-Environmental Sciences,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了探讨岷江干旱河谷丛枝菌根真菌（AMF）对寄主植物幼苗根系的影响，通过接种购买的AMF摩西球囊霉菌（Funneliformis mosseae）到优势乡土灌木小马鞍羊蹄甲（Bauhinia faberi var. microphylla）幼苗，在重度、中度和轻度干旱条件下培养3个月，研究不同干旱条件下AMF对幼苗根系形态特征、结构特征、功能性状的影响。方差分析结果表明：（1）3种干旱胁迫条件下，接菌均显著增加了幼苗的根总长、根表面积、根分枝数、根尖数（P < 0.001），在中度胁迫和轻度胁迫下，接菌显著促进根鲜重、根体积的增加（P < 0.001），轻度胁迫条件下接菌幼苗的根鲜重、根总长、根表面积、根体积、根尖数最高并显著高于其它处理，但接菌与未接菌的根平均直径之间没有显著差异；（2）接菌幼苗根系趋向于叉状分支结构，在重度胁迫时，叉状分支趋势更显著（P < 0.001）；（3）接菌幼苗的根比例都显著小于未接菌的，但幼苗比根长不存在显著差异。相关分析结果表明：菌根侵染率与根鲜重、根总长、根表面积、根体积、根分枝数、根尖数呈极显著正相关（P < 0.001），与拓扑指数、根比例呈极显著负相关（P < 0.001）。研究表明，在干旱条件下，AMF虽然没有提高生长初期的根系的吸收效率，但接种AMF显著影响幼苗根系形态特征和结构特征，更利于植物适应干旱环境，并且AMF对幼苗根系的促生作用随着干旱胁迫程度减轻而提高。 Abstract:Arbuscular mycorrhizal fungi (AMF) can develop a symbiotic relationship with the roots of most terrestrial plants, which can improve the drought tolerance of the host plants. Based on our previous studies, AMF play a critical role in promoting native plant growth in the arid valley of the Minjiang River, China. Furthermore, the effects of AMF on root growth are as important as their effects on aboverground growth. To understand how plant roots respond to AMF under different drought stress conditions, we designed a completely randomized full factorial pot experiment in a greenhouse in the arid valley of the Minjiang River. We added one common AMF (Funneliformis mosseae, FM) to the roots of seedlings from a dominant native shrub (Bauhinia faberi var. microphylla), using three different drought stress conditions. Continuous drought stress was induced by watering the seedlings with distilled water at one-day intervals for three months at low (40%), medium (60%), and high levels (80%) of the field capacity. At the end of the experiment, we harvested the seedlings, and cleaned their roots with distilled water. We subsequently measured the root fresh weight, scanned the roots with a root scanner (EPSON 11000XL), and obtained variables such as root length, root surface area, root volume, root forks, and number of root tips with WinRhizo. We subsequently analyzed the root architecture and the functional characteristics of the B. faberi seedlings to address the relationship between root development and AMF presence under different levels of drought stress. We used one-way ANOVAs, two-way ANOVAs, LSD fitting methods, and Pearson's correlations for our statistical analyses. Inoculation of FM significantly increased the total root length, root surface area, root forks, and the number of root tips under all three drought stress conditions (P < 0.001). In addition, under medium and high soil water content, it significantly increased root fresh weight and root volume (P < 0.001). More specifically, high soil water conditions resulted in the significantly highest root fresh weight, total root length, root surface area, root volume, and number of root tips after FM addition. Nonetheless, there was no significant difference in average root diameter between inoculated and non-inoculated seedlings. Inoculated seedlings tended to develop a dichotomous branching style, which was more profound at low (40% of field capacity) soil water content (P < 0.001). Furthermore, the root fractions of inoculated seedlings were significantly smaller than the non-inoculated seedlings (P < 0.001). However, there was no significant difference in specific root length among all the treatments. Root fresh weight, root length, root surface area, root volume, root forks, and number of root tips correlated significantly and positively with colonization rate (P < 0.001). In contrast, topological index and root fraction were significantly and negatively correlated with colonization rate (P < 0.001). Overall, we found that, although AMF did not improve the root absorption efficiency in the initial growth period of B. faberi, AMF presence significantly affected seedling root morphology and root functional characteristics. These latter effects enhanced B. faberi seedling growth, which allowed the plants to adapt to drought conditions. Finally, the positive effects of AMF on root growth increased with improving water conditions. 参考文献 相似文献 引证文献