Diversity Of Endophytic Fungi Of Five Flower Plants In Yunnan And Its Effect On Plant Growth

Fungi causing asymptomatic infections in living plant tissues have been called endophytic fungi. Endophytic fungi widely distributed in plants tissues. In one hand, the plant provides hydrogencarbon for fungi, on the other hand, the endophytic fungi can enhance the plant growth, improve its capacity against various biotic and abiotic stresses through producing a variety of bioactive metabolites. It was estimated that about 50% of the fresh cut flower of China was produced in Yunnan province, however, little was known on the diversity and its ecological roles of the endophyte of Yunnan flowering plants. In the present study, the biodiversity and plant-growth-promoting ability of endophytic fungi from five flowering plants growing in Yunnan province was reported.1. A total of 357 endophytic fungi was isolated from 1000 segments of healthy leaves and stems of five plant species. Based on the morphological characteristics and the ITS sequence analysis, the isolates were identified to 24 taxa, of which Alternaria, Phomopsis, Cladosporium and Colletotrichum were the dominant genera, and the relative frequencies of them were 21.57%,17.36%, 5.04% and 5.04% respectively. The Shannon-Weiner diversity index of endophytic fungi from the five plant species ranged from 1.73-2.45, which indicated that the endophytic fungal diversity of flowering plants is rich.2. R. rugosa, C. japomica and D. regia growing in wild harbored more fungi than R. hybrid and D. caryophyllus planted in greenhouse. It may be due to the fertilizer and pesticide which was widely used in greenhouse.3. Twenty four isolates from five flowering plants and eight isolates from Yuanjiang dry-hot valley were selected to test their plant-growth-promoting ability, and the results showed that 50% of strains from the flowering plants and 25% of the strains from Yuanjiang dry-hot valley exhibited different plant-growth-promoting effect.4. The isolates H25(Phomopsis sp.), B50 (Sterile mycelium), A38(Alternaria sp.) and A7 (Alternaria sp.) which exhibited better plant-growth-promoting ability, were subjected to a further pot experiment. The results indicated that the isolate A38 had a obvious plant-growth-promoting effect. The height, fresh weight, dry weight and content of soluble sugar of the plant inoculated with A38 increased 25.15%、64.98%、67.50% and 21.43% when compared whih CK. The results indicated that the isolate A38 may have a potential use in the flowering plant cultivation.