The Research Of Ectomycorrhizal Fungi Collaborate With Actinomycetes From Mycorrhizosphere Of Pinus Tabulaeformis On Damping-off

In this study, strains of actinomycete which not only resist the damping-off pathogen, but also promote the growth of ectomycorrhizal fungi were isolated from Pinus tabulaeformis mycorrhiizosphere soil samples collected from Huoditang Forest Region, QinLing, Shaanxi, China. Morphological characteristics and cultural characteristics, physiological and biochemical characteristics test and 16SrDNA gene sequence were used to classify actinomycete strains. Confirming the optimum combination of actinomycete, ectomycorrhizal fungi and pathogen, and make them in different treatmens infect Pinus tabulaeformis. Observing the protective effect of ectomycorrhizal fungi and actinomycete on damping-off, and surveying the influence of different treatments on the growth of Pinus tabulaeformis. The major results were described as follows:1. Screening of actinomycete resisted pathogenic fungi and promoted ectomycorrhizal fungiOne hundred and seventy different actinomycete strains were isolated from eleven Pinus tabulaeformis mycorrhizosphere soil sample. By antagonistic effect in petri dish tests, two fungus(R. solani, F. solani) known as damping-off potential pathogens were used.Results showed that 7 strains of actinomycete had strong inhibitory effect toward these two pathogens. The anti-microbial effect reached 60.18~80.57% and 51.25~73.96%. And by confrontation effect in petri dish tests, two strains of actinomycete promoted the growth of ectomycorrhizal fungi are isolated from seven strains of actinomycete. In petri dish tests of three kinds of microorganisms we confirm the optimum combination of actinomycete, ectomycorrhizal fungi and pathogenic fungi: AV, 110 and RS.2. Identification of actinomycete resisted pathogenic fungi and promoted growth of ectomycorrhizal fungiAccording to their morphology, physiological and biochemical characteristics, molecular biology identifications, and 16SrDNA sequence analysis, the results indicated that: The substrate mycelium of the strain 19 is slender and have branches, no diaphragm and no broken, and interwoven into the mesh, the aerial mycelium become the spore chain and the spore chain have the form of a helix. It could grow well on Gause's Synthetic Agar, Czapek's Agar, Glucose Asparagine Agar, Glucose Yeast Extract Agar, Potato Dextrose Agar and Potato medium, but could not grow on K's 1 culture medium. Gelatin become liquid and litmus milk become red by it. It could decompose sulfur-containing amino acids and produce hydrogen sulphide. It could grow heterotrophically on organic carbon sources such as sucrose, fructose, mannose, inositol, glucose, but could not hydrolyze starch and cellulose. Combined with the result of 16SrDNA sequence analysis, we confirm that the strain 19 is Streptomyces mauvecolor. The substrate mycelium of the strain 110 break along with the direction of perpendicular to the long axis of hyphal, all aerial myceliums of the strain 100 break into spore chains. It could grow well on Gause's Synthetic Agar, Czapek's Agar and Potato Dextrose Agar, relatively poor on K's 1 culture medium, but could not grow on Glucose-Asparagine Agar, Glucose Yeast Extract Agar and Potato. It could not make gelatin liquid. It could not decompose sulfur-containing amino acids and produce hydrogen sulphide. It could make litmus milk red. It could grow heterotrophically on organic carbon sources such as sucrose, mannose, but not fructose, inositol, glucose, It could hydrolyze starch, but not cellulose. Combined with the result of 16SrDNA sequence analysis, we confirm that the strain 110 is Nocardiopsis umidischolae.3. Protective effect of ectomycorrhizal fungi and actinomycete on pine damping-off,and inoculating effect of different treatments on Pinus tabulaeformisThree kinds of microorganisms were re-inoculated on the host Pinus tabulaeformis in 8 different treatments: inoculated with AV; inoculated with 110; inoculated with RS; inoculated with AV and 110; inoculated with AV and RS; inoculated with 110 and RS; inoculated with AV, 110 and RS; inoculate nothing as contrast(CK). The results show that the protective effect of 110 and AV on damping-off is the best, up to 83.93%. The protective effect of AV on damping-off is 69.64%,the protective effect of 110 is 62.5%. The effect of different treatments on promoting the growth of the host is: inoculated with 110 and AV is the best,the treatment inoculated with AV, the treatment inoculated with AV, 110 and RS and the treatment inoculated with 110,the treatment inoculated with AV and RS and the treatment inoculated with 110 and RS come next. The effects of treatment inoculated with CK is relatively poor. The effects of treatment inoculated with RS is the worst.