| Soil microecological changes affect the stability of soil ecosystem, the relationship between soil microecological variation and plant soil-borne diseases is a new study field. Panax notoginseng has become a valuable medicinal herbs. In recent years, with the continuous cropping obstacles occurring in Panax notoginseng, the soil-borne disease is increasingly prominent. For the control of soil-borne disease, applying high dose pesticide deteriorate the producing areas of Panax notoginseng. The contradiction between Panax notoginseng industrial development and soil ecological environment has become the main barrier in drug industry healthy and sustainable development. This paper aims to study diseased soil microbial diversity and its associations with soil-borne diseases, comparative study of microbial diversity, species differences between Panax notoginseng healthy and root rot plants, soil salinity and salt concentration impact on the distribution of microorganisms, screening of probiotics and extraction of active substance and so on. This study was designed to prevent medicinal plants cropping obstacles to achieve ecological planting Panax notoginseng and provide a scientific basis and new prevention strategies.In order to reveal the reality of microbial diversity, this research analysis method conducted on the basis of the combined regular cultivation and DNA molecule extraction. Particularly, in terms of microbial molecular genetic diversity analysis, it combined the anatomy on gene amplification and sequencing of both prokaryotic microorganisms 16 S r DNA gene and eukaryotic 18 S r DNA. The results showed that: it’s about 296 bacterial strains were isolated from 4 samples(Yanshan and Qiubei in Yunnan), among them prokaryotic microorganism distributed to 4 phyla, 40 genera of bacteria. 168 strains from the samples of healthy Panax notoginseng rhizosphere soil, they were classified to 30 genera, and most of them belong to Burkholderia, Arthrobacter, Streptomyces and Bacillus. Additionally, the samples of root rot Panax notoginseng rhizosphere soil were gained 92 strains which belong to 29 genera, and Ralstonia, Sphingomonas, Stenotrophomonas as the dominant microflora. Although the proportion of fungi is smaller, but the fungal richness and abundance in the samples of root rot Panax notoginseng rhizosphere soil are much richer than healthy Panax notoginseng. Besides that this study has found a potential novel species.In order to research the antibacterial activity of the dominant microflor between healthy and rot root soil around Panax notoginseng rhizosphere, variety of pathogenic fungi were as indicator. 3 strains were selected, which have antagonism to various plant pathogenic fungi. After application of experimental verification, has applied for a patent strain(a kind of Burkholderia bacteria and its application in soil borne disease prevention and control of Panax notoginseng); the ions concentration and electrical conductivity value show distinct discrepancy between the healthy Panax notoginseng rhizosphere soil and root rot Panax notoginseng rhizosphere soil(P < 0.05); the microbial amount of dominant species in the healthy soil samples present negative correlation with electrical conductivity value, the concentration of NO3-, SO42-, CO32-, K+ and total salt(P < 0.01).This study shows that: in addition to pathogen infection, the physical and chemical characteristics, microbial community structureand the proportion of dominant species are also closely related to Panax notoginseng continuous cropping soil borne disease. Study the Panax notoginseng rhizosphere of microbial ecosystem, explore the probiotics to prevent Panax notoginseng pathogen and exploit microbial agents to against Panax notoginseng continuous cropping obstacle have a bright future.
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