Page 148 - 《广西植物》2023年第3期
P. 148
5 4 8 广 西 植 物 43 卷
Abstract: The response of arbuscular mycorrhizal fungi (AMF) colonization rate to slope position and shrub species in
karst slope and the key influencing factors were identifiedꎬ which is the prerequisite for rational utilization of soil AMF to
promote karst vegetation restoration. Based on field investigation of typical shrub communities and environmental
variables on slopes of a karst peak cluster depression. The fine root samples of three typical shrub species ( Vitex
negundoꎬ Alchornea trewioides and Pyracantha fortuneana) were collected from three positions ( upperꎬ middle and
lower) along three slopes. The frequencyꎬ intensity and abundance of AMF colonization were detected and calculated by
the Trypan blue ̄microscope method. The results were as follows: (1) The colonization frequencyꎬ colonization intensity
and abundance of AMF for Vitex negundo and Alchornea trewioides were higher than those for Pyracantha fortuneana in
the same slope. The colonization intensity for Vitex negundo and Pyracantha fortuneana in the lower slope was higher than
that in the upper and middle slopes. The abundance of AMF for Alchornea trewioides in the middle slope was significantly
higher than that in the upper and lower slopes (P<0.05). (2) Shrub species had significant effect on the colonization
frequencyꎬ intensity and abundance of AMFꎬ and slope position only had significant effect on the colonization intensity of
AMF. Slope position and shrub species had significant interactive effect on the abundance of AMF (P<0.05). (3) Soil
depth and total potassium content were identified as the two strongest explanatory factors on AMF colonization rate
according to the redundancy analysis (P<0.05). Thereforeꎬ the rational use of soil AMF to promote vegetation restoration
in karst areas needs to consider the choice of terrain and speciesꎬ and should pay attention to the water and soil
conservation. The results of this study provide a scientific basis for rational utilization of the symbiotic relationship
between soil AMF and plants and promoting ecological restoration of karst peak cluster depression.
Key words: karstꎬ arbuscular mycorrhizal fungiꎬ frequencyꎬ intensityꎬ abundance
丛 枝 菌 根 真 菌 ( arbuscular mycorrhizal fungiꎬ 染率较高ꎮ 同时ꎬAMF 作为植物的共生真菌ꎬ其宿
AMF) 能 与 地 球 上 大 约 80% 的 植 物 形 成 共 生 体 主植物种类是影响 AMF 侵染的重要因素( 杨康
(Smith & Smithꎬ 2011)ꎬ具有扩大根系范围、促进 等ꎬ2019)ꎮ 由于不同植物生物学特征与生态习性
植物养分吸收和提高植物抗旱性等生态功能( 米 等方面存在差异ꎬ因此必然会影响丛枝菌根真菌
屹东等ꎬ2020ꎻKang et al.ꎬ 2020ꎻ刘娜等ꎬ2021)ꎮ 对宿主植物的侵染(梁月明等ꎬ2018)ꎮ 例如ꎬ红锥
因此ꎬAMF 在退化或破坏的生态系统恢复重建中 和单性木兰根系 AMF 侵染率显著高于紫弹树(张
得到广泛应用(魏源等ꎬ2012)ꎮ 海波等ꎬ2016)、香椿的侵染率显著高于茶条木( 张
西南喀斯特地区岩溶作用强烈ꎬ土层浅薄且 中峰等ꎬ2018)ꎻ灌丛既是喀斯特峰丛洼地的主要
不连续ꎬ生态环境极其脆弱ꎬ是我国水土流失最严 植被类型ꎬ又是喀斯特植被恢复的关键阶段( 胡芳
重的地区之一(黄同丽等ꎬ2019)ꎻ其退化生态系统 等ꎬ2018)ꎻ在喀斯特峰丛洼地坡地ꎬ灌木优势植物
恢复最重要的任务是植被恢复( 李先琨等ꎬ2003)ꎮ 根系中的 AMF 侵染率会随坡位而发生改变ꎬ这种
其中ꎬ峰丛洼地是植被恢复最快的地貌类型( Tong 改变可能会因植物而异ꎮ 因此ꎬ研究喀斯特坡地
et al.ꎬ 2020)ꎬ坡地占比超过 70%ꎮ 受地质和地貌 典型灌木物种 AMF 侵染率对坡位的响应ꎬ对于深
背景的制约ꎬ引发坡地快速水文过程ꎬ喀斯特地区 入理解植物与 AMF 互作关系并合理利用 AMF 促
土壤层较薄且不连续ꎬ岩溶渗漏致使土层水肥保 进该区植被恢复具有重要意义ꎮ
持能力差、土壤贫瘠(李先琨等ꎬ2008)ꎮ 不同坡位 本文选取广西环江典型喀斯特峰丛洼地的 3
的土壤养分等条件往往存在巨大差异( 李先琨等ꎬ 个坡位(上、中、下坡位)和 3 个优势灌木物种黄荆
2003ꎻ梁月明等ꎬ2017)ꎬ显著影响 AMF 的基本特 (Vitex negundo)、红背山麻杆( Alchornea trewioides)
征ꎬ如侵染率( 张中峰等ꎬ2015ꎻ屈明华等ꎬ2021)ꎮ 和火棘( Pyracantha fortuneana) 作为研究对象ꎬ测
侵染率是表征菌根真菌与宿主植物是否建立共生 定不同坡位的土壤理化性质以及植物根系 AMF 侵
关系的重要指标ꎬ主要包含菌根侵染频度、侵染强 染频度、侵染强度和丛枝丰度等侵染率参数ꎬ明确
度和丛枝丰度等参数( 任禛等ꎬ2014)ꎮ 王淼焱等 坡位与灌木物种对 AMF 侵染率是否存在交互作
(2006)研究表明ꎬ土壤中磷含量较低时 AMF 的侵 用ꎬ以及影响 AMF 侵染率的主要因素ꎬ为合理利