Effect of Microwave Mutagenesis on the Growth and Salt Tolerance of Trichoderma T-LJ and T-YM

Purpose To obtain the highly efficient growth and salt-tolerant mutant strains of Trichoderma.

Methods Two Trichoderma strains (T-LJ and T-YM) isolated from saline-alkali soil were used as the original strains. Based on the colony diameter of the strains and the simulated salt stress of NaCl solution, the microwave mutagenesis parameters of the mutagenic strains were screened, and their salt tolerance characteristics were analyzed.

Results Compared with the original strains, the mutagenesis for 60 s showed the best growth promotion effect on the Trichoderma strain T-LJ, with the colony diameter increasing 60.0%; the mutagenesis for 15 s showed the best growth promotion effect on the Trichoderma strain T-YM, with the colony diameter increasing 33.3%. The colony diameter of Trichoderma strain T-LJ was significantly increased when the mass concentration of NaCl was 20-50 mg/mL and the mutagenesis time was 75 s, especially when the mass concentration of NaCl was 20 mg/mL, the colony diameter increases the most significantly, increasing by 20.0% to the original strain. The colony diameter of Trichoderma strain T-YM increased by 30.8% to the original strain, when the mass concentration of NaCl was 20 mg/mL and the mutagenesis time was 30 s; and when the mass concentration of NaCl was greater than 20 mg/mL and the mutation time was between 30 to 60 s, the colony of the Trichoderma strain T-YM was significantly larger than the original strain.

Conclusion The key microwave mutagenesis parameters for affecting the growth and high salt tolerance of Trichoderma strains T-LJ and T-YM are obtained in this study.