The Studies On Soil-Microorganism Biodiversity And Biological Pest Control Strains Of Medicinal Plant In Liaoning Province

Liaoning Province is located in the joint zone of three flora of changbai mountain, north China and Mongolia,which enjoys nature-endowed geographic environments and biological resources in planting Chinese herbal medicine.The development of Chinese herbal medicine is one of main methods for peasants to increase income in the eastern mountain area of Liaoning.The main medicinal plants in Liaoning Province are schisandra,asarum,dioscorea, panax,gentiana,aconitum,fritillaria,lilium,astragalus,saposhnikovia,atractylodes,polygonatum, clematis,dictamnus,etc.The soils of nearly 20 species of the medicinal plant were studied in this paper.The differences among different medicinal plants were analyzed.The species and quantity of fungi,bacteria and antinomycete in soil of medicinal plants were clear.With the pathogen of main diseases of medicinal plants as target,the strains in the control of pathogen were screened from soil of medicinal plants.The main results are as follows.1.The quantity of culturable microorganisms in medicinal plants' soil was analyzed. The results showed that the main reason affecting the number of microorganisms in soil was root exudates of medicinal plants,and next came soil fertility and planting pattern.The effect of changes of seasons was subtle.The soil microorganisms of perennial medicinal plants were more than of annual and biennial ones.The results showed that the soil microorganisms number of the 14 4-year-old medicinal plants decreased in the order of aconitum,dioscorea, schisandra,fritillaria,lilium,panax,astragalus,saposhnikovia,atractylodes,gentiana,asarum, polygonatum,clematis,dictamnus.2.The composition of phospholipid fatty acid(PLFA) can be used as 'signatures' to analyze changes in microbial communities structure and microbial biomass.PLFA content of soil microorganisms of schisandra increased with the increase of planting age;PLFA quantity of healthy schisandra were slightly higher than those of infected ones.PLFA content of 4 medicinal plants decreased in the order of aconitum,dioscorea,astragalus,schisandra.PLFA content of 5-year-old panax were obviously higher than those of 2-year-old ones.The dominant species of al and a2 were 14:0,i15:0,a15:0,16:0,16:1w7t,17:0,18:0,a18:0, 18:1w7,cy19:0 and 20:0;3.185 fungi strains were isolated from soil of 14 4-year-old medicinal plants,which belonged to 30 genera.Among them the frequency of Fusarium,Trichoderma and Penicillium were higher and could be isolated from all 14 medicinal plants.The frequency of Fusarium, Cylindrocarpon and Rhizoctonia inducing root disease were higher,too.The results indicated that the diversity of soil fungi of medicinal plants related with species and using parts of medicinal plants,and had no obvious relationship with geographic environment.Lilium and fritillaria might be the most closely related species,and dictamnus and dioscorea might be farthest.4.The dominant fungi species from 63 medicinal plants soil samples were identified through morphological methods.The results showed that 10 species of Fusarium were identified,among them Fusarium oxysporum was the dominant one;9 species of Trichoderma were identified,among them Trichoderma harzianum was the dominant one;7 species of Penicillium were identified,among them Penicillium janthinellum was the dominant one.5.109 bacteria strains were isolated from soil of 14 4-year-old medicinal plants,which belonged to 17 genera.Most of them were gram-negative bacteria.4 genera of gram-positive bacteria were identified,among them Bacillus was the dominant one.213 antinomycete were isolated,of which Streptomyces,Nocardia,Streptosporangium,Micropolyspora and Micromonospora were identified.The dominant genera was Streptomyces.The results indicated that the diversity of soil bacteria of medicinal plants might be related with species, using parts of medicinal plants and geographic environment.Clematis and panax might be the most closely related species,and astragalus,schisamdra and atractylodes might be farthest.6.3 bacteria,4 antinomycete and 1 Trichoderma against 5 target pathogen were screened from soil of medicinal plants.The screened bacteria and antinomycete could cause the deformation of pathogen hyphal growth in different degree.The phenomena of Vesicles, swelling and protoplasm leaking out were observed.The germfree ferment filtrate could inhibit hyphal growth and spore germination of pathogen.The inhibition rate of Trichoderma T1 against 5 pathogen were all over 75%.T1 could decompose the pathogen hypha through interweaving,penetrating,invading and paralleling.Good biocontrol strains are widely distributed in medicinal plant soil.The results provides theoretical base for biocontrol of medicinal plant disease.