Effects of two fungicides on Neotyphodium seed-borne fungal endophyte of Festuca sinensis

Festuca sinensis, a good quality and cold tolerant forage in alpine region of China, was studied to explore the effect of two systemic fungicides on fungal endophyte of F.sinensis at different concentrations and times. Thiophanate-methyl (TM) and difenoconazole (D) had five concentrations and four distinct times respectively. The result of germination experiment indicated that 8 h was the most reasonable. Meanwhile, 500, 300-fold dilution TM and 3000, 1 000-fold dilution D were considered to be effective treatments for a next experiment with the 8 h. The result revealed that the order of endophyte infection of seedling was: 3 000 D500 TM300 TM1 000 D; the order of germination rate of seedling was: 300 TM500 TM3 000 D1 000 D. The sterilization of 300 and 500-fold dilution TM was significant (P0.05) and had no adverse effect on germination rate,endophyte infection of seedling was reduced from 98% to 7% and 10%. The 8 h treatment of 1 000 and 3 000-fold dilution D reduced germination rate significantly (P0.05) from 79% to 54% and 63%, and at the same time, endophyte infection was reduced significantly (P0.05) from 98% to 5% and 30%. Therefore, the solution of 300-500-fold dilution thiophanate-methyl treated seeds in 8 h was the best way to eliminate fungal endophyte of F.sinensis.