Sun Yuqing, Zhang Xin, Wu Zhaoxiang, Hu Yajun, Wu Songlin, Chen Baodong
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2016 Jan;39:110-118. doi: 10.1016/j.jes.2015.10.005. Epub 2015 Dec 7.
Arbuscular mycorrhizal fungi (AMF) can establish a mutualistic association with most terrestrial plants even in heavy metal contaminated environments. It has been documented that high concentrations of toxic metals, such as arsenic (As) in soil could adversely affect the diversity and function of AMF. However, there are still gaps in understanding the community composition of AMF under long-term As contaminations. In the present study, six sampling sites with different As concentrations were selected in the Realgar mining area in Hunan Province of China. The AMF biodiversity in the rhizosphere soils of the dominant plant species was investigated by sequencing the nuclear small subunit ribosomal RNA (SSU rRNA) gene fragments using 454-pyrosequencing technique. A total of 11 AMF genera were identified, namely Rhizophagus, Glomus, Funneliformis, Acaulospora, Diversispora, Claroideoglomus, Scutellopora, Gigaspora, Ambispora, Praglomus, and Archaeospora, among which Glomus, Rhizophagus, and Claroideoglomus clarodeum were detected in all sampling sites, and Glomus was the dominant AMF genus in the Realgar mining area. Redundancy analysis indicated that soil pH, total As and Cd concentrations were the main factors influencing AMF community structure. There was a negative correlation between the AMF species richness and the total As concentration in the soil, but no significant correlation between the Shannon-Wiener index of the AMF and plants. Our study showed that high As concentrations can exert a selective effect on the AMF populations.
丛枝菌根真菌（AMF）即使在重金属污染环境中也能与大多数陆生植物建立共生关系。有文献记载，土壤中高浓度的有毒金属，如砷（As），会对AMF的多样性和功能产生不利影响。然而，在理解长期砷污染下AMF的群落组成方面仍存在差距。在本研究中，在中国湖南省雄黄矿区选择了六个砷浓度不同的采样点。通过使用454焦磷酸测序技术对核糖体RNA小亚基（SSU rRNA）基因片段进行测序，研究了优势植物物种根际土壤中的AMF生物多样性。共鉴定出11个AMF属，分别为根内球囊霉属（Rhizophagus）、球囊霉属（Glomus）、漏斗球囊霉属（Funneliformis）、无梗囊霉属（Acaulospora）、多样孢囊霉属（Diversispora）、类球囊霉属（Claroideoglomus）、盾巨孢囊霉属（Scutellopora）、巨孢囊霉属（Gigaspora）、双型囊霉属（Ambispora）、原囊霉属（Praglomus）和古孢囊霉属（Archaeospora），其中球囊霉属、根内球囊霉属和明球囊霉（Claroideoglomus clarodeum）在所有采样点均被检测到，球囊霉属是雄黄矿区的优势AMF属。冗余分析表明，土壤pH值、总砷和镉浓度是影响AMF群落结构的主要因素。AMF物种丰富度与土壤总砷浓度呈负相关，但AMF的香农-威纳指数与植物之间无显著相关性。我们的研究表明，高砷浓度可对AMF种群产生选择作用。
