黑龙江省药用植物根际土壤真菌多样性

Abstract

Heilongjiang Province is one of the major medicinal plant-growing areas in China.In order to understand the population structure and distribution characteristics of fungal species in rhizosphere soil of cultivated medicinal plants,the authors investigated and collected 220 rhizosphere soil samples in the fields of 14 medicinal plants grown in Yichun,Tieli,Suihua,Harbin,Mudanjiang and Jiamusi regions of Heilongjiang Province during July to October,2010.The mainly investigated medicinal plants included Acanthopanax senticosus,Anemarrhena asphodeloides,Arctium lappa,Belamcanda chinensis,Bupleurum chinense,Carthamus tinctorius,Codonopsis pilosula,Dioscorea nipponica,Fritillaria ussuriensis,Leonurusa artemisia,Platycodon grandiflorus,Saposhnikovia divaricata,Schisandra chinensis,and Scutellaria baicalensis.In this paper,we took the traditional morphological methods to identify fungal species.This study is aimed at the following three aspects: to investigate the detailed species and distribution pattern of sporulating fungi in rhizosphere soil of cultivated medicinal plants in six regions of Heilongjiang Province,to analyze the fungal diversity in rhizosphere soil of different medicinal plants,to collect potentially economic fungal resources,and to understand ecological characteristics of rhizosphere soil fungi of medicinal plants in the studied areas. After fungal isolation by means of soil dilution plate and soil particle plate and culture on standard media,totally 1016 fungal isolates were obtained.Based on colony and spore production,86 fungal species belonging to 35 genera were morphologically identified,including ten species in seven genera of Zygomycetes(7.78%),two species in one genus of Ascomycetes(0.69%),and 74 species in 27 genera of anamorphic fungi(70.76%),the left 20.77% of all isolates were sterile on media.The results indicated that plentiful fungal diversity was present in the cultivated medicinal plant rhizosphere soil in Heilongjiang Province.Of which the species in Penicillium,Aspergillus,Trichoderma and Fusarium were the predominant groups of fungi,their relative isolating frequencies were 16.93%,14.76%,8.46% and 6.69% respectively.The species of Gliocladium,Chrysosporium,Mucor,Cladosporium,Acremonium and Rhizopus were the subdominant groups,their relative frequencies were 5.02%,4.23%,4.13%,3.74%,2.36% and 2.26% respectively.The fungal population structures and compositions were different in the rhizosphere soil of all the medicinal plants.Penicillium,Aspergillus,Trichoderma and Fusarium occured in all the 14 investigated medicinal plants,and they were the predominant groups,but their distribution frequencies were different in different medicinal plants.The plentiful fungal isolates of Trichoderma and Gliocladium cultured from the rhizosphere soil of various medicinal plants were of economical significance for bio-control of medicinal plants soil-borne diseases and bio-transformation of Chinese herbal medicines. The medicinal plants of Schisandra chinensis,Fritillaria ussuriensis and Bupleurum chinense were most extensively cultivated in Heilongjiang Province,and the fungal diversities in the rhizosphere soil of the above three medicinal plants all grown in six investigated regions were significantly different.Yichun was the highest in Shannon diversity index(H′=2.9574) and Margalef richness index(R=5.6683).Jiamusi was the highest in Pielou evenness index(J=0.9200).The fungal diversities in the six regions were different in similarity.It ranged from 0.3704 to 0.6315,and of which the similarity coefficient of fungal populations in medicinal plant rhizosphere soil was higher(Cj=0.6315) for Mudanjiang and Suihua,while it was lower for Mudanjiang and Harbin(Cj=0.3704).Our results showed that the factors such as cropping patterns of medicinal plants,climate and soil environment evidently affected the fungal diversity and similarity in the rhizosphere soil of medicinal plants.