The fungal strain Trichoderma sp. Xy24 was isolated from the leaves, stems and peels of mangrove plant X. granatum collected in Sanya district, Hainan province of China. The fungal strain was maintained on slants of modified potato dextrose agar (PDA) medium (potato 200 g, glucose 20 g, distilled water 1 L, KH₂PO₄ 3 g, MgSO₄ 0.75 g, vitamin B1 10 mg, agar 8.0 g, pH 6.0; the media were autoclaved at 115 ℃ for 30 min) at 4 ℃. Seed cultures were performed in Erlenmeyer flasks (250 mL) containing 100 mL of PDA liquid medium on a shaker at 150 rpm at 25 ℃ for 2 days, after that 5 mL seed cultures were inoculated into each 1000 mL flask with 300 mL medium and cultivated for 14 days (150 rpm, 25 ℃).