Studies On Ecological Characters And Biological Characters Of Species In Genus Lophodermium On Pine Tabulaeformis In The East Of Liaoning Province

Pine tabulaeformis is one of the major trees in the east of Liaoning province, and large areas of Pine tabulaeformis are appeared both in natural and artificial forests. Recently, the needle cast of Pine tabulaeformis has occurred wildly in the east of Liaoning forest region, and severely threatened Pine tabulaeformis's growth in some area. The authors had an investigation on this disease in major Pine tabulaeformis areas, and found that Lophodermium spp. was the pathogenic fungi which caused the needle cast. Lophodermium spp. is an important part in the fungi. In this present thesis, ecological characteristics and biological characteristics of some species of Lophodermium spp. were systematically studied with the techniques of modem mycology and forest pathology. Including the research of the needle cast of Pine tabulaeformis and description of the symptom, the effect of entironmeng on the disease, the observe and analysis biological characteristics of these species of Lophodermium spp.More than 40 samples collected from the east of Liaoning province(include Shenyang, Fushun, Benxi, Dandong)come to 12 places were sorted, cultured, and indentified by their morpHologic characteristics to species and cultured. Based on the classification standard proposed by Minter, five species of Lophodermium genus were indentified. They were L. conigenum(brunaud)Hilita, L. pinastri(Schrad)Chev, A₂, Xin2B, L. nitens Darker. These kind of fungi fruit bodies develop on recently dead for instrusion or decayed plant materials. In this article 4 fungi were studied.The relation between entironment and pathogeny was: the orientation of slope was unconspicuous for the needle cast. The position of slope, stand composition, stand density and crown density had conspicuous relation to the disease. Downgrade was more severe than upgrade. The pure forest had worse disease than mixture plantation and mixture natural forest. With the bigger of stand density, goingwith crown density turnned to smaller, the disease aggravated. vice versa. There are some relation between agrotype and pathogeny, also: the incidence of the disease and the exponent of the disease of the lithoid brown forest soil were higher than dark-brown forest soil. With the aggravater of the disease the content of quick result nitrogen and pHospHorus, calcium, magnesium decreased. the most conspicuous was the content of nitrogen. The pH show a weak acid level. The disease stand extent increasing went with the incresed acid level.The Lophodermium fungi were isolated by tissue isolation. Effect of culture medium, pH value, temperature, light on The Lophodermium fungi were researched. Culture characters data of 4 species were obtained. PDA was the best culture medium for growth of the kind of fungi. Most formed pycnidia earlier onCA. and OA, PDA and PSA, PA, PAS formed pycnidia later, but the diameter of pycnidia on PDA and PSA were larger than CA, OA, PA, PAS. None of the species can produce ascocarps in 60 days. The optimum pHvalue was 5.5 or 6.0, Most LopHodermium fungi could also growth in 4.0-10.0 pH value; Effect of light on the LopHodermium fungi was unconspicuous. They could grow in 2-35℃, the best temperature for them was 25℃, they couldn't grow in 35℃. On the premise of consulting historical documents,the life history, the harmfulness,ecological and biological characteristic were summarized and discussed.The methods of prevention and cure the needle cast were concluded.At last,wish the study can give some help to the Needle Cast of P. tabulaeformis.