Study On Endophyte In Conifer In The Midwest Inner Mongolia

Endophytic fungi are separated from five conifers including Pinus tabulaeformis Carr.,Pinus sylvestnis var.mongolica Litv.,Picea asperata Mast.,Juniperus rigida Sieb,et Zucc and Larix gmelinii Rupr.,sampled from 7 western regions of Inner Mongolia. Basing identification, the species diversity is analyzed and the prevailing strains are experimented for getting their physiological property and selecting fungal antagonists. The results show that:1.By means of experiment,1810 strains are separated from the confier samples, among which 583 stains cannot be observed spore-bearing and the rest identified pertain to 51 genus. To be specific,490 strains are separated from the samples of Pinus tabulaeformis Carr. , 404 stains from Pinus sylvestnis var.mongolica Litv.,359 stains from P.meyeri, 345 stains from Juniperus rigida Sieb,et Zucc and 212 stain from Larix gmelinii Rupr..Among the fungi, Alternaria sp.and Penicillium sp. are the prevailing genus, respectively accounting for 21.93% and 17.02%.2. In terms of sampling part,the number of strains separated from petiole is largest and that from fruit is le least;in term of crown level,the numbers of stain and genus in upper layer are largest,the next is in midst layer and the least is in under layer; in term of age, the numbers of stain and genus take on the following regular pattern:1～5 year-old<5～10 year-old<10～20 year-old<20～30 year-old<30～40 year-old;in term of species diversity,the highest rate is from Pinus tabulaeformis Carr.of Hohhot and the lowest is from Larix gmelinii Rupr.of Xiaojingou.3.The physiological properties of the two prevailing genus, Alternaria sp.and Penicillium sp.,are gained after experiment. The optimum temperature of Alternaria sp. is 30℃, while the the optimum temperature of Penicillium sp. is 25℃.The principal carbon source of Alternaria sp. is glucose while the principal carbon source of Penicillium sp. is sucrose.The principle nitrogen source of the two genus is peptone.Through the experiment for the optimum medium, it is learned that the nitrogen source plays a great role in the growth of Alternaria sp. while the caobon source can brings about an obvious effect on the growth of Penicillium sp., and the mycelia dry masses of the two genus both have a positive correlation with the mass concentration of medium and sugar. on the 4. On the experiment of plating culture for antagonism and of spore germination,it is visible that the 4 genus separated from five conifers ,in addition to their metabolites,all have obvious antagonism to pathogenic bacteria. The inhibiton rate of Penicillium sp. to Rhizoctonia sp.,Cytospora chrysosperma and Coniothyrium sp.are notable (P<0.05), respectively accounting for 67.96%, 65.91% and 61.12%. To Fusarium sp.,the inhibiton rate of Coniothyrium sp. is the largest up to 76.38%.