基于高通量测序的两种典型忽地笑栽培土壤根际真菌群落多样性

Fungal diversity in two typical types of rhizosphere cultivation soil of Lycoris aurea based on high-throughput sequencing

摘要:

【背景】忽地笑为传统中药材，可用于治疗老年性痴呆症、重症肌无力等疾病，具有重要的药用价值。腐殖土(壤土)适宜忽地笑的生长与栽培，黄棕壤(粘性土)对其生长不利。根际微生物可促进或抑制植物生长，直接影响药用植物产量和有效成分含量的变化，因此近年来对药用植物与根际微生物关系的研究得到了高度重视。【目的】通过2种栽培土壤根际真菌的群落结构及多样性研究，旨在探讨根际真菌对忽地笑生长发育的影响。【方法】提取土壤总DNA，采用高通量测序及生物信息统计分析等方法进行研究。【结果】腐殖土和黄棕壤分别获得真菌ITS1序列42 130和30 176条；腐殖土和黄棕壤根际真菌类群分别划分为6门25纲61目123科208属和5门20纲48目85科138属，最优势门类均为子囊菌Ascomycota (相对丰度>70%)，但主要优势属及多样性指数等存在较大差异，其中腐殖土的主要优势类群有Ascomycota_unclassified、Fusarium、Zopfiella、Chaetomiaceae_unclassified、Ceratobasidium、Mortierella等，而黄棕壤的主要优势类群为Sordariomycetes_unclassified、Fusarium、Acremonium、Rhizoctonia、Nectriaceae_unclassified、Hymenoscyphus等；通过SPSS统计软件分析表明，腐殖土的Ascomycota_unclassified、Zopfiella、Ceratobasidium、Mortierella等优势类群与忽地笑鳞茎中石蒜碱含量之间呈极显著正相关性。【结论】适宜栽培忽地笑的腐殖土根际真菌的遗传多样性比黄棕壤更丰富；腐殖土根际主要优势类群Ascomycota_unclassified、Zopfiella、Ceratobasidium等可能有利于忽地笑生长发育及其石蒜碱等生物碱积累。

Abstract:

[Background] Lycoris aurea is a traditional Chinese medicinal herb plant commonly used to treat several diseases including Alzheimer’s disease and myasthenia gravis etc.which has important medicinal value. The plant grows vigorously in humus soil (loam), but its growth performance in yellow-brown (clay) soil is very poor. In the recent years, increasing attention has been given to the investigations on the interrelations between medicinal plants and their rhizospheric microorganisms because the microorganisms played important roles for the growth, development and accumulation of biological active components of medicinal plants. [Objective] To study the effects of rhizospheric fungi on growth of L. aurea, we analyzed fungal community structure and genetic diversities cultivated in two soils. [Methods] Soil microbial total DNA was extracted. The community structure and diversity were analyzed by using high-throughput sequencing etc. [Results] Total of 42 130 and 30 176 fungal ITS1 sequences were obtained from humus soil and yellow-brown soil, respectively. Rhizospheric fungi in humus soil and yellow-brown soil could be classified as follows: 6 Phyla, 25 classes, 61 orders, 123 families, 208 genera and 5 phyla, 20 classes, 48 orders, 85 families and 138 genera, respectively; among which, the most predominant Phyla both were Ascomycota (relative abundance > 70%). The dominant genera and their diversity indexes etc. were different between humus soil and yellow-brown soil. Ascomycota_unclassified, Fusarium, Zopfiella, Chaetomiaceae_unclassified, Ceratobasidium, Mortierella, etc. were predominant groups in humus soil. But there were significant differences in predominant groups of yellow-brown soil, including Sordariomycetes_unclassified, Fusarium, Acremonium, Rhizoctonia, Nectriaceae_unclassified, Hymenoscyphus etc. Among which, there was a significant positive correlation among Ascomycota_unclassified, Zopfiella, Ceratobasidium, Mortierella etc. predominant groups in humus soil and lycorine content in bulbs of L. aurea by using SPSS statistical software. [Conclusion] The genetic diversity of rhizospheric fungi in humus soil that is favorable for cultivation of Lycoris aurea were richer and higher as compared to those of yellow-brown soil. Its predominant fungal groups such as Ascomycota_unclassified, Zopfiella and Ceratobasidium etc. may be favorable for the growth and lycorine accumulation of Lycoris aurea.