Page 148 - 《广西植物》2022年第3期
P. 148
4 9 2 广 西 植 物 42 卷
Abstract: Salinty and alkali are the serious stress in arid and semiarid areaꎬ which has a bad effect on plant growth. It is
necessary for us to explore the variety of microbial community and the activity of enzyme in rhizosphere of Pennisetum
giganteum(giant juncao) under saline ̄alkali environment. As a resultꎬ we set up the experiment with seven different
kinds of saline ̄alkali concentrationsꎬ analyze the difference significance and correlation of physiological data under
different saline ̄alkali concentrations with the method of SPSSꎬ and analyzed the diversities of microbial communities with
the method of Illumina high ̄throughput sequencing. The results were as follows: (1) The composition of microbial
communities in rhizosphere soil of giant juncao differed at different saline ̄alkali stressesꎻ The dominant groups were
Sordariomycetes (68.5%)ꎬ Eurotiomycetes (16.3%)ꎬ Chloroflexia (8.5%)ꎬ Bacteroidia (13.5%)ꎬ Gemmatimonadetes
(5. 6%) and δ ̄Proteobacteria ( 3. 7%) at the 12‰ saline ̄alkali concentrationꎻ The relative abundance of the
Dothideomycetes (27.7%)and Anaerolineae (2.4%) was sharply reduced to 2.5% and 0.007% when the saline ̄alkali
concentration increased from 6‰ to 12‰ꎻ The Chao and Shannon indexes of the rhizosphere microbial community of
giant juncao decreased with increasing saline ̄alkali concentrationꎬ and were significantly correlated with soil saline ̄
alkali concentration (P<0.01). (2) The low concentration of saline ̄alkali stress had a positive effect on activities of
ureaseꎬ polyphenol oxidase and alkaline phosphatase in rhizophere soil of giant juncaoꎬ but activities of polyphenol
oxidaseꎬ alkaline phosphatase and sucrase were inhibited when the saline ̄alkali concentration of soil exceeded 8‰ꎻ
After planting giant juncaoꎬ the content of soil organic matter increased significantly (P<0.05) and the saline ̄alkali
concentration were reduced significantly (P<0.05)ꎻ The neutralizing ability to soil alkalinity gradually weakened with
the increasing saline ̄alkali concentrationꎬ and the neutralizing ability of soil salinity gradually weakened when the
concentration exceeded to 8‰ꎻ When the saline ̄alkali concentration was 6‰ꎬ the production of giant juncao was the
highest and the soil had higher contents of available nutrients and organic matter. The research indicates that growing
giant juncao is beneficial to improving the fertility of saline ̄alkali soil by adjusting the enzyme concentration to better
adapt to the medium and low concentration saline ̄alkali soil environmentꎬ and producing the corresponding dominant
flora to adapt to the environment in different degrees of saline ̄alkali soil.
Key words: saline ̄alkali stressꎬ soil microorganismsꎬ physical and chemical propertiesꎬ soil fertilityꎬ salt ̄tolerant plant
盐碱地由盐土和碱土组成ꎬ可溶性盐浓度达 表面的酶(关松荫等ꎬ1986)ꎮ 土壤肥力、理化性质、
0.6%及以上的土壤叫做盐土ꎬpH 值超过 9ꎬ交换性 植被和微生物种类与数量是影响土壤酶活性的主
钠离子浓度达到阳离子总代换量 20%及以上的土 要因素ꎮ 土壤盐碱化可以改变土壤的一些理化性
壤叫做碱土( 张鹏辉等ꎬ2017)ꎮ 根据联合国教科 质ꎬ可直接影响微生物的生存(Mo et al.ꎬ 2016)ꎬ也
文组织及世界粮农组织的统计显示ꎬ当前全球的 可间接影响土壤微生物的生境ꎬ使微生物的种群、
盐碱地主要分布在欧亚大陆、非洲和美洲西部ꎬ总 数量和活性以及土壤酶活性等方面受到损害ꎬ导致
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面积约为 9.54×10 hm ꎮ 我国的盐碱地总面积已 土壤微生态失衡ꎬ从而影响作物生产( Chen et al.ꎬ
经多达9 913 × 10 hm ꎬ分布于我国 23 个省( 自治 2004)ꎮ 因此ꎬ研究土壤酶活性和微生物的影响因
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区)和市ꎬ已经占据了我国国土总面积的 10%( 王 素对植物更好地生长具有重要意义ꎮ
景立等ꎬ2018)ꎬ该现状已严重威胁到我国的生态 菌草是指适合作为食用菌、药用菌培养基并有
环境与粮食安全ꎬ研究出一种合适且具有生态效 综合开发利用价值的草本植物 ( 林占熺ꎬ2013)ꎮ
益的改良方法已迫在眉睫ꎮ 1989 年ꎬ菌草开始应用于生态改良ꎬ主要用于砒砂、
土壤根际微环境是土壤中的特殊微域之一ꎬ也 崩岗和 沙 地 的 治 理 ( 林 占 熺 等ꎬ 2019)ꎮ 彭 露 等
是植物获取养分的主要区域ꎮ 在这块区域里ꎬ植 (2014)利用菌草耐盐碱的特性ꎬ将其作为改良和利
物、微生物、土壤相互作用(Ma et al.ꎬ 2015)ꎮ 研究 用盐碱土地的作物并进行了初步的研究ꎬ发现巨菌
发现ꎬ土壤酶和微生物是土壤根际微环境中的活跃 草能在盐碱土地等生态脆弱地区种植并能快速成
组分ꎬ对自然或人为因素造成的变化响应比较敏感 为优势种ꎬ对当地土壤生态环境起到一定的改良作
(Xie et al.ꎬ 2007)ꎮ 土壤酶包括微生物细胞和动植 用ꎮ 林兴生等(2013aꎬb)、潘羿壅等(2018) 初步研
物残体的胞内酶以及土壤溶液和吸附在土壤颗粒 究了盐碱胁迫对菌草生理指标的影响ꎬ筛选出了抗