Page 162 - 《广西植物》2025年第11期
P. 162

2 1 0 6                                广  西  植  物                                         45 卷
                 Abstract: Arenaria bryophyllaꎬ which is mainly distributed in extreme environments at an altitude of about 5 000 mꎬ is
                 one of the important Xizang medicinal plants in the plateau region. To explore the bacterial diversity in the rhizosphere
                 soil of A. bryophylla in the Qiangtang grassland of northern Xizangꎬ Chinaꎬ this study used high ̄throughput sequencing
                 technology to investigate the diversity and community composition of rhizosphere soil bacteria from A. bryophylla at
                 different sites. The results were as follows: (1) There was no significant difference in the α ̄diversity of rhizosphere soil
                 bacteria among the three sampling sitesꎬ but the bacterial community composition was significantly different ( P <
                 0.05). The dominant phyla of the bacterial communities in the rhizosphere soil at all three sampling sites were
                 Proteobacteria and Firmicutesꎬ while the composition of dominant genera differed. Correlation network analysis showed
                 that the connections within the rhizosphere soil bacterial communities were mainly positiveꎬ indicating synergistic
                 effects. (2) Light intensityꎬ ammonium nitrogenꎬ available phosphorusꎬ and organic matter significantly affected the
                 composition of bacteria in the rhizosphere soil of A. bryophylla ( P < 0. 05)ꎬ with light intensity having the highest
                 explanatory power. (3) Predictions of COG functional gene families and KEGG metabolic pathways showed that amino
                 acid transport and metabolismꎬ and carbohydrate transport and metabolism were the dominant functionsꎬ and there were
                 significant differences in the dominant functional genes among different regions (P< 0.05). In conclusionꎬ there are
                 significant differences in the composition of the bacterial community in the rhizosphere soil of A. bryophylla in different
                 regions of the Qiangtang Plateau. Environmental factors such as light intensity significantly affect the bacterial community
                 compositionꎬ and the functions of rhizosphere soil bacteria in different regions show differentiation. This study provides a
                 theoretical basis for the research on A. bryophylla as a traditional Xizang medicine on the Qinghai ̄Xizang Plateauꎬ and
                 also provides a reference for further understanding the adaptive evolution of A. bryophylla to the harsh environment of the
                 Qinghai ̄Xizang Plateau.
                 Key words: Arenaria bryophyllaꎬ rhizosphere soil bacteriaꎬ community compositionꎬ diversityꎬ functional prediction


                 雪 灵 芝 是 木 兰 纲 ( Magnoliopsida ) 石 竹 目         2007)ꎮ 根际土壤聚集的微生物有细菌、真菌、病
            (Caryophyllales)石竹科( Caryophyllales) 老牛筋属          毒、藻类和原生动物等ꎬ其中细菌的数量最多ꎬ根际
            (Eremogone)的多年生垫状草本植物ꎬ是当今生长                        微生物参与根际土壤中的物质循环与能量流动ꎬ包
            海拔最高的绿色开花植物之一ꎬ也是一种极为宝                              括碳、氮、磷、硫等养分的循环和土壤有机质的分解
            贵的 野 生 藏 药 植 物 ( 李 易 强ꎬ 2016ꎻ 刘 增 根 等ꎬ             (Young & Carwfordꎬ 2004ꎻ Raaijmakers et al.ꎬ 2009ꎻ
            2016)ꎮ 藓状雪灵芝( Arenaria bryophylla) 作为雪             邓增卓玛等ꎬ2022)ꎬ是连接土壤与植物的重要媒
            灵芝的一种ꎬ生长在海拔 5 000 m 左右的高寒草                         介ꎬ根际微生物也被称为植物的第二基因组ꎬ植物
            甸、石灰岩山地草原或石缝间ꎬ主要分布在西藏、                             根际微生物的群落构建及其与植物的互作研究是
            青海、滇西北等地ꎮ 先前的研究表明ꎬ雪灵芝富含                            近年来微生物领域的热点之一ꎮ 青藏高原地区海
            生物碱及多种维生素ꎬ有抗炎、抑菌及免疫调节等                             拔高、温度低、紫外线强和缺氧ꎬ被称为“地球第三
            作用(陈薇和段小群ꎬ2009ꎻ 伍贤学等ꎬ2013ꎻ 李易                      极”ꎬ是全球生物多样水平最高的地区之一ꎮ 该地
            强ꎬ2016)ꎮ 同时ꎬ该植物长期适应高海拔缺氧环                          区的植物与微生物通过相互作用来适应极端环境ꎮ

            境ꎬ进化出良好的抗氧化能力( 苏红卫等ꎬ2002ꎻ                          细菌在青藏高原植物根际土壤微生物群落中占有
            张丽等ꎬ2007ꎻ 柳丽等ꎬ2009)ꎮ 关于藓状雪灵芝                       重要位置ꎬ在山莨菪根际土壤微生物群落的组装和
            的研究仅限于其化学成分ꎬ如宋丹丹等(2021) 对                          功能研究中ꎬ细菌是整个根际土壤微生物群落中不
            藓状雪灵芝乙酸乙酯部位的化学成分研究ꎬ目前                              同微 生 物 类 群 之 间 的 重 要 纽 带 ( Wang et al.ꎬ
            尚未见有关藓状雪灵芝根际土壤微生物群落结构                              2024)ꎻ冰川棘豆的内生菌的相关研究表明ꎬ核心内

            和多样性的研究报道ꎮ                                         生细菌连接的紧密性和土壤特性等因素可以调控
                 根际是指受根系分泌物直接影响强烈ꎬ在理化                          植物的生命活动(曹鹏熙等ꎬ2020)ꎮ
            性质和生物学特性上明显地不同于原土体的土壤                                  植物根际微生物群落组 成 受 植 物 物 种 多 样
            微区域ꎬ以该土壤区域为生存环境条件的所有微生                             性、土壤特性、气候因素等多方面影响( Zhang et
            物就是 根 际 微 生 物 ( 刘 子 雄 等ꎬ 2005ꎻ 王 天 龙ꎬ              al.ꎬ 2022ꎻ 马坤ꎬ2023)ꎬ对环境变化非常敏感ꎬ环
   157   158   159   160   161   162   163   164   165   166   167