人参根际真菌群落多样性及组成的变化

Changes of diversity and composition of fungal communities in rhizosphere of Panax ginseng

连作障碍导致人参减产减收,影响人参产业的可持续发展。土壤真菌群落参与关键生态过程,其多样性及组成的变化与连作障碍相关。该研究采用高通量测序技术,分析人参根际土壤真菌群落多样性及组成的变化,阐述人参栽培模式对根际微生态的影响,为克服连作障碍提供策略。与森林土壤相比,人参根际土壤微生物多样性增加,且随着种植年限的增加,多样性增加趋势下降;真菌群落Sordariomycetes,Alatospora,Eurotiomycetes,Leotiomycetes,Saccharomycetes,Mucorales,Pezizomycetes的丰度增加。皮尔森相关分析表明,土壤理化指标影响人参根际真菌群落的丰度,pH与Dothideomycetes和Alatospora的丰度显著相关,有效钾含量与Dothideomycetes,Alatospora,Mucorales的丰度显著相关,土壤总氮含量与Sordariomycetes,Mucorales的丰度显著相关。结果表明,施肥是影响人参根际微生态的关键因素之一,优化施肥体系是克服人参连作障碍的有效途径之一。

Continuous cropping obstacles resulted in the yield losses of Panax ginseng,and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process,and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method,stated the effects of ginseng cultivation on the micro-ecology,and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils,the fungal diversity of ginseng rhizosphere soils was increased,and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes,Alatospora,Eurotiomycetes,Leotiomycetes,Saccharomycetes,Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson＇s correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes,Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng,and optimization of fertilization system was an effective method to overcome continuous cropping obstacles.