Fungal Diversity In Rhizosphere Soil Of Medicinal Plants In Heilongjiang Province

Heilongjiang province is one of the major medicinal plants-growing areas in China. The total production and sales amount of traditional Chinese herb medicine accounts for about15%of the total quantity in China. Its production and marketing play a vital role in the national herbal medicine market. Of the various herbs, the planting area of Schisandra chinensis, Fritillaria ussuriensis and Bupleurum chinense are widely cultivated. In recent years, the soil-borne diseases are becoming serious duo to increase in cultivation areas and continuous cropping index of various medical plants. The diseases significantly affect the quantity and quality of medical plants. The microorganism number, species and mycobiota in rhizosphere soil are different because of the specific chemical compounds secreted by the rootlets of medical plants at different developing stages. In the current study, the traditional morphological methods was used to identify fungal species. It is also aimed to investigate the fungal diversity in rhizosphere soil of medical plants in Heilongjiang province, and to understand the main fungal species in soil and their distribution characteristics. By the way some economically invaluable fungal resources will be screened for potential utilization in field of soil-borne diseases bio-control and chemical compound bio-transformation.During July to October of2010and2011,380rhizosphere soil samples were collected in the fields of18medicinal plants grown in Jiagedaqi, Wudalianchi, Beian, Nehe, Yichun, Tieli, Suihua, Harbin, Wuchang, Mudanjiang and Jiamusi regions of Heilongjiang province. The mainly investigated medicinal plants included Schisandra chinensis, Fritillaria ussuriensis, Acanthopanacis senticosus, Codonopsis pilosula, Saposhnikovia divaricata, Bupleurum chinense, Platycodon grandiflorus and Scutellaria baicalensis. After fungal isolation by means of soil dilution plate and soil particle plate and culture on standard media, totally1235fungal isolates were obtained. Based on colony and spore production,102fungal species belonging to40genera were morphologically identified, including ten species of seven genera of Zygomycetes, six species of two genera of Ascomycete, and86species of31genera of Anamorphic fungi, the left of all isolates were sterile fungi. Of which two species are newly recorded in China, they are Acremonium pteridii (J. C. Frankland) W. Gams and Chrysosporium anamorph of Arthroderma cuniculi (Dawson) C.A.N.van Oorschot. The test results indicate that plentiful fungal diversity was present in the cultivated medicinal plants rhizosphere soil in Heilongjiang province. Of which the species of Penicillium, Aspergillus, Trichoderma and Fusarium were the predominant groups of fungi, and the species of Gliocladium, Chrysosporium, Mucor, Cladosporium, Acremonium and Rhizopus were the subdominant groups of fungi.The medical plants of Schisandra chinensis, Fritillaria ussuriensis and Bupleurum chinense were most extensively grown in Heilongjiang province, 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 eveness index (J=0.9200). The fungal diversities in the six regions were different in similarity. It ranged from0.3704to0.6315, and of which the similarity coefficient of fungal populations in medicinal plant rhizosphere soil was higher (Cj=0.6315) for Suihua and Mudanjiang, while it was lower for Harbin and Mudangjiang (Cj=0.3704).The test result shows that the cropping system of medicinal plants imposed predominant control impact on fungal diversity and similarity of the rhizosphere soil, and the climate conditions and soil types also affected the fungal diversity.