宁夏贺兰山东麓老龄葡萄园土壤真菌群落结构分析

Soil fungal community structures in aged vineyards at the eastern foot of Helan Mountain in Ningxia

【目的】对宁夏贺兰山东麓老龄葡萄园土壤真菌群落物种组成及多样性进行研究,明析老龄葡萄园葡萄根际土壤真菌群落特征,为老龄葡萄园的科学管护和可持续发展提供依据。【方法】采集宁夏贺兰山东麓种植20年葡萄园不同土层(0~20,20~40和40~60 cm)的根际土壤(分别记为CS20、CS40和CS60)与非根际土壤(分别记为NCS20、NCS40和NCS60),采用CTAB法提取土壤基因组DNA,对内转录区间(ITS1-ITS2)扩增后进行高通量测序,测定土壤真菌群落组成和物种多样性,分析土壤真菌群落结构的变化特征。【结果】群落分布丰富度指数(Chao1和ACE)分析表明,根际土壤中的真菌群落丰富度均高于非根际土壤,且二者存在显著差异(P<0.05);群落分布多样性指数(Shannon)分析表明,在0~20 cm土层根际与非根际土壤间多样性存在显著性差异(P<0.05),其余土层二者差异不显著。葡萄根际土壤与非根际土壤真菌分属17门、47纲、109目、211科、346属,门水平上优势真菌为子囊菌门(Ascomycota)、被孢霉菌门(Mortierellomycota)和担子菌门(Basidiomycota),平均相对丰度分别为51.04%,5.68%和4.89%。在属分类水平上,根际土壤中新丛赤壳菌属(Neonectria)、Dactylonectria属、小球腔菌属(Leptosphaeria)、假裸球囊菌属(Pseudogymnoascus)真菌的平均相对丰度分别是非根际土壤的174.5,122.2,156.0和133.3倍,而非根际土壤中镰刀菌属(Fusarium)、青霉菌属(Penicillium)、Zopfiella属真菌是根际土壤的4.4,77.8和277.0倍。Weighted Unifrac距离指标分析表明,根际土壤各土层间(CS20、CS40和CS60)物种多样性差异较小,而非根际土壤各土层间(NCS20、NCS40和NCS60)物种多样性差异较大。【结论】宁夏贺兰山东麓老龄葡萄园葡萄根际土壤真菌群落分布丰富度较非根际土壤有所增加,真菌优势物种富集,根际土壤垂直土层间物种多样性差异减小,不利于维持根际土壤真菌群落的微生态平衡;病原菌Dactylonectria属和新丛赤壳菌属相对丰度增加,而镰刀菌属相对丰度降低,葡萄植株患病机率增大。

【Objective】 This study investigated the species composition and diversity of soil fungal community and analyzed the characteristics of grape rhizosphere soil fungal community in aged vineyards at the eastern foot of Helan in Ningxia to provide basis for scientific management and sustainable development of aged vineyards.【Method】 The rhizosphere soil(CS20,CS40 and CS60) and non-rhizosphere soil(NCS20,NCS40 and NCS60) were collected at the vertical depths of 0-20,20-40 and 40-60 cm from grapes at the age of 20 years at the eastern foot of Helan in Ningxia.Soil genomic DNA was extracted by CTAB method and amplified by internal transcription interval(ITS1-ITS2) for high-throughput sequencing.The composition and species diversity of soil fungal community were measured and the change characteristics of soil fungal community structure were analyzed.【Result】 The analysis of community distribution abundance indexes(Chao1 and ACE) showed that the abundance of fungal community in rhizosphere soil was higher than that in non-rhizosphere soil with significant differences(P<0.05).The analysis of community distribution diversity index(Shannon) showed that there was significant difference between rhizosphere and non-rhizosphere soil only at 0-20 cm(P<0.05).The fungi in grape rhizosphere soil and non-rhizosphere soil belonged to 17 phylum,47 class,109 order,211 family and 346 genus.At the phylum level,the dominant fungi were Ascomycota,Mortierllomycota and Basidiomycota with the average abundance of 51.04%,5.68% and 4.89%,respectively.At the genus classification level,the average relative abundance of Neotectria,Dactylonectria,Leptosphaeria and Pseudonymnoacus in rhizosphere soil was 174.5,122.2,156.0 and 133.3 times higher than those in non-rhizosphere soil,respectively,while those of Fusarium,Penicillium and Zopfiella in non-rhizosphere soil was 4.4,77.8 and 277.0 times higher.The Weighted Unifrac distance index showed that the difference of species diversity among rhizosphere soil layers(CS20,CS40 and CS60) was small,but the difference of species diversity among non-rhizosphere soil layers(NCS20,NCS40 and NCS60) was large.【Conclusion】 The distribution abundance of fungal community in grape rhizosphere soil was higher than that in non-rhizosphere soil at the eastern foot of Helan Mountain in Ningxia.The dominant species of fungi enriched and the difference of species diversity between vertical layers of rhizosphere soil reduced,which was not conducive to maintaining the microbial balance of rhizosphere soil fungal community.The abundance of Dactylonectria and Neoectoria increased,while that of Fusarium decreased,which increased the probability of grape plant diseases.