The Preliminary Research Of Aquatic Plant Endophytes In Southwest China

Endophytic fungus plays an important role in increasing biomass of plant and tolerance of plant to environment pressure. Many studies have focused on endophytic fungus of terrestrial plants, and gave few attention to endophytic fungus of aquatic plants which have broader distributions. Limited researches show that endophytes of aquatic plants embrace higher biodiversity and differ from those in terrestrial species, which also are important in helping plants to resist environment pressure. What’s more, aquatic plants are a good model in surveying impact of geographic patterns and environmental gradients on biodiversity, and studies on distribution pattern of endophytic fungus in aquatic plants will help further exploration of biodiversity. In this study,31 abundant aquatic plants species were collected from some lakes in Yunnan, Sichuan and Guizhou Province in southwest China in August 2014 and 2015. Culture endophytic fungi were isolated and identified combining morphological and molecular method.The results as following:1. A total of 1697 isolates were isolated from 15,373 plant tissue segments, and 1341 isolates were identified, which are referable to 156 genera,74 families,35 orders, and 14 classes across 4 phyla, showing the significant diversity of endophyte in aquatic plants sufficiently.2. Comparing to endophyte from terrestrial plants, there are more fungi of Basidiomycota such as Necator, Phaeophlebiopsis, and also more aquatic in composition of aquatic plant endophytes, such as Setophaeosphaeria, Heydenia.18 genera fungi haven’t been founded in terrestrial plants.3. Isolation frequency and species diversity differed significantly among different species of aquatic plant, among tissue types of same species and among aquatic ecosystems. To different ecosystem, the highest isolation frequency is 19.6% from Fuxian Lake, and lowest one is 2.4% of Wuxu Lake. To different plant, Trapa bispinosa is the highest (60%) and Nymphoides peltatum is the lowest (5.2%). Focus on tissue types of same plant, the highest is 11.5% and the lowest is 10.5%, occurred on leaves and stems respectiveily.4. Isolation frequency and species diversity of endophyte differed among different latitudes significantly. In general, the higher the latitude is, the lower the diversity and isolating frenquence in general. The highet isolation frequency value (13.15%) occurs between 1000 and 2000m, and the lowest (9.72%) is between 2000 and 3000m. The highest diversity value occurs between 2000—3000m (5.33) and the lowest is above 4000m (4.55).5. A great proportion of the dominiant endophytes are pathogens, such as Colletotrichum, Cladosporium and Cytosporina. These fungi were isolated from lakes where human activity are frequent and economical plants distributed near by.