Characteristics Of Epichlo? Endophyte-Festuca Sinensis Symbiote

In the present study, seeds of six Festuca sinensis ecotypes were collected from west regions of China including Gansu, Qinghai and Sichuan province and the endophyte infected rate were tested which reached 100%. The endophyte infected(E+) and endophyte free(E-) populations of these ecotypes were set up in field. The growth parameters including plant height, tiller number and biomass and endophyte and lolitrem concentrations were measured to test the effects of endophyte on Festuca sinensis. The main results are as follows:1. Epichlo? endophyte had significantly improved germination and vigor of Festuca sinensis seeds under NaCl stress.The results showed that NaCl stress treatments within 50-200 mmol/L significantly reduced the seed germination rate, interim germination, germination index, the length of embryo and radicle and dry weights of both E+ and E- seeds. Endophyte had significantly improved seeds germination and seedling growth under different concentrations of NaCl. There were interaction effects between seed hydro-priming and the Epichlo? endophyte. The highest level of interaction were with 20 mins seed hydro-priming, when germination indices and seedling growth rates were significantly higher than all the other treatments. Correlation analysis showed that F. sinensis seed germination rate, interim germination, germination index, the length of embryo and radicle and dry weight were all significantly positively related to each other.2. There were significant difference in the growth perforemance and improvement effect of Epichlo? endophyte caused by host ecotypes and genotype of Epichlo? endophyte. There were significant difference between these 6 ecotypes E+ populations or E- populations for the growth indices including height, tiller, dry weight, leaf ratio, seed yield and seed germination rates which suggested the strong impacts of host genotypes on associations performance(P<0.05). Only for two ecotypes, Epichlo? endophyte improved host growth performance, which demonstrated the different genotypes had different effects(P<0.05).3. There was close relationship between host ecotypes and genotype of Epichlo? endophyte. The phylogenetic tree was constructed with actin gene sequences cloning from the tested Festuca sinensis endophyte and the published actin gene sequences in GenBank. The results showed that the Epichlo? endophyte isolated from eight Festuca sinensis ecotypes clustered together and formed a separated clade, suggesting that Epichlo? endophyte in different Festuca sinensis ecotypes could be the same and new species. Population genetic distance analysis certified that these 8 strains maybe the same genus.4. Host ecotypes had significant effects on endophytes concentrations. Peramine concentrations were significant differences between different ecotypes(P<0.05). However, there was no significant difference between lolitrem B concentrations of different ecotypes excepted 99 ecotype(P>0.05). The content of lolitrem B in tested 6 Festuca sinensis ecotypes ranged from 0.8 to 1.2 ppm. There was no significant correlation between the concentrations of peramine and lolitrem B(P>0.05).In the conclution, the study clearly demonstrated that host ecotypes and genotype of Epichlo? endophyte have the effect on the growth of Epichlo? endophyte-Festuca sinensis symbiont. The Epichlo? endophyte-Festuca sinensis symbiont can produce two kind of alkaloids that were loliterm B and peramine. These research is the foundation of selection resilience toxic strain for the next step.