绿色木霉制霉菌素抗性菌株的紫外光诱导

UV-Induced Resistant Strains of Trichoderma viride to Nystatin

生防菌进入土壤中所在的位置及定殖的能力大小是制约生防菌剂能否商业化应用的主要原因。为了获得耐药性绿色木霉,进一步确定该生防菌在土壤中的定殖能力,通过紫外光照射诱变野生型绿色木霉菌株,结合使用含制霉菌药培养基进行耐药性筛选,得到了绿色木霉抗性突变菌株,制霉菌素的最低抑菌浓度为1×10-2g/mL。抗性菌株在无药培养基上连续转移培养8次,抗性程度未见下降,但生长速度降低。抗性菌株保持了对魔芋软腐病的拮抗能力。同时表明,耐药性木霉菌株在土壤中的定殖密度随时间的变化呈现先上升后下降的趋势。

The mutants resistant to nystatin were obtained by UV light induction on PDA amended with nystatin from a wild isolate of Trichoderma viride. Resistant level was over 200 times in comparison with that of the original strain. The mutants could maintain their resistance after be shifted 8 times on the fungicide free PDA, but the growth speed reduced. The resistant strains retained the ability of an- tagonism against plant pathogenic Erwinia carotovora in vitro and in vivo. The colonization density of 7＇. viride in rhizospheres of displayed a descending trend as the change of time. Overall, T. viride can col- onize in the soil and satisfy its bio-control demand.