Study On The Pathogen And Pollution-free Control Of Dry Shrink Of Seabuckthorn In Heilongjiang Province

Sea-buckthorn( Hippophae rhamnoides L.) is a kind of principal tree species for dune fixation afforestation, nature remodeling and landscaping. Especially recent years Hippophae rhamnoides has been still taken as pioneer tree species of the construction of forest ecological projects by "the three norths shelter belt system project".With the cultivated areas of Sea-buckthorn being expanded continuously, the diseases of Sea-buckthorn increasingly serious, especially the Dry Shrink of Seabuckthorn which is the most serious and truculency disease in the world, made a great deal of Sea-buckthorn plants to death.The methods of mycology, forest pathology, molecular biology and community ecologywere used to study the pathogen and pollution-free control of dry shrink of Seabuckthorn, The results show as follows:(1) The pathogen which causes Dry Shrink of Seabuckthorn. in Heilongjiang Province is Fusarium sporotrichioides To the pathogen, the optimium growth temperature is 25℃, the optimium growth pH is 7,the optimium growth carbon source is maltose and the optimium growth nitrogen souce is sodium nitrate and peptone; the optimium sporification temperature is 25℃, the optimium sporification pH is 6, the optimium sporification carbon source is lactose and the optimium sporification nitrogen is sodium nitrate.(2) The pathogen of Dry Shrink of Seabuckthorn in Heilongjiang Province could grow on the different parts of Seabuckthorn plants. There were differences in pathogenicity among the pathogen strains which growing at different parts. The pathogenicity of the strains growing in trunk is the highest. There were some genetic differentiations inside of the pathogen species.(3) A total of 37 taxa fungiwere recognized from samples from Seabuckthorn plants., 14from leaves, 11 from branches, 11from trunks, 7 from roots, they belong to 3 phylum, 6 class, 14 famiy, 21genes.The fungi diversity is go up from the root to leaf. The tree inhabiting fungi had important affection on the growth of pathogen of dry shrink of Seabuckthorn. Alternaria tenuis and Fusarium chlamydosporum had significant inhibiting effect to pathogen growth. Trichoderma atroviride had better inhibiting effect to pathogen growth, and Phoma herbarum had gowth-promoting effect to pathogen.(4) The occurrence of dry shrink of Seabuckthorn related with the nutrition. Calcium fertilizer, foliar fertilizer containing multi-elements, boron fertilizer, phosphorus-potassium fertilizer and Si-Zn Fertilizer all could reduce the incidence of the disease, especially Calcium which could resist the pathogen infecting and remarkably reduce incidence of the desease. The lack of calcium in soil was one of the important inducements to the occurrence of dry shrink ofSeabuckthorn. Calcium fertilizer could reduce 50% of the Dry Shrink of Seabuckthorn.