Study on the diversity of growth rate of endophytes isolated from Fescue spp. on different media

Our main goals were to further develop and utilize the endophytes of Festuca, select suitable media for the growth of endophytes, and compare the growth rates of different strains. Accordingly, we established multiple types of growth media conditions with different pH (4, 5, 6, 7, 8, 9, and 10), different carbon sources (glucose, maltose, lactose, D-xylose, D-sorbitol, and soluble starch), different nitrogen sources (peptone, tryptone, sodium nitrate, ammonium nitrate, urea, ammonium oxalate, and potassium nitrate), and different media (potato dextrose agar PDA, potato sucrose agar PSA, Czapek agar, corn meal agar CMA, and water agar WA). Eleven endophyte strains of the genus Epichloë isolated from Festuca plants (strain ID: G1, G2, G3, G4, 291-4, 291-14A, 1, 2, 9, 57A, and 84F) were selected and cultured on these different media to explore the differences in the growth rates of the aforementioned strains under different cultivation conditions. The results showed that the type of medium and pH had significant effects on the growth and sporulation rates of the endophytes (P < 0.05). The optimum pH range for growth of the 11 endophytes was 4～7. The strongest carbon source was D-sorbitol, and the strongest nitrogen source was peptone. PDA and PSA were the most appropriate media for mycelial growth. Strains 1 and 2 grew fastest, strain 291-4 and strain 291-14A grew slowest.