OBJECTIVETo analyze the effects of continuous cropping and soil treatment on rhizosphere fungal community of Panax quinquefolium, and the correlation between rhizosphere fungal community and growth of P. quinquefolium.

METHODField plot trail of continuous cultivated P. quinquefolium was conducted, meanwhile continuous cropping soil was treated by organic carbon fertilizer plus methylene dithiocyanate and Kingbo respectively. The rate of seedling survival, root disease index and root weight were investigated. Dilution plating was used to analyze the rhizosphere fungal community, multiple comparisons including H, M(a) and J were performed between rhizosphere fungal community and growth of P. quinquefolium.

RESULTAs to P. quinquefolium planted in continuous soil, the rate of seedling survival, root weight decreased, root disease index increased remarkably (P<0.05). Meanwhile the fungal counts decreased 50% -63% , the diversity index (H') decreased 39%-43%, while the ratio of Penicillium and Aspergillus increased. There was a significant negative correlation between rhizosphere fungal diversity and P. quinquefolium root disease index (r = -0.970, P=0.006). Organic carbon fertilizer plus methylene dithiocyanate treatment could improve the rate of seedling survival and root weight, and could partly increase the rhizosphere fungal diversity.

CONCLUSIONIn continuous cropping soil of P. quinquefolium, the rhizosphere fungal counts and diversity index decreased, meanwhile the fungal community composition changed. Organic carbon fertilizer plus methylene dithiocyanate treatment could improve the growth of continuous cultivated P. quinquefolium.