生防菌与茄病镰刀菌在黄瓜根际动态变化

应用荧光定量PCR和稀释分离法检测了枯草芽孢杆菌Bacillus subtilis和木霉菌Trichoderma spp.与茄病镰刀菌Fusariumsolani f.sp.cucurbitae在黄瓜根际动态变化及其对黄瓜根腐病的防治效果。结果表明,施用500×木霉菌肥、100×枯草芽孢杆菌7d后对黄瓜根腐病的防效分别为100%和92.5%,14和28d的防效分别为96.71%、86.76%和85.35%、79.24%;100×枯草芽孢杆菌初始拷贝数为130787 copys/μL,7d内枯草芽孢杆菌拷贝数下降到51161 copys/μL,14和28d时数量开始上升到295139和680556 copys/μL。木霉菌肥的变化趋势与枯草芽孢杆菌相同;用枯草芽孢杆菌和木霉菌肥防治黄瓜根腐病后,茄病镰刀菌变化趋势一致,初始拷贝数分别为2.61和15.34 copys/μL,7d内茄病镰刀菌DNA拷贝数增加明显,100×枯草芽孢杆菌和木霉菌DNA拷贝数分别为11.22和20.9 8copys/μL,之后茄病镰刀菌数量保持平稳。经过稀释分离法分离2种生防菌和茄病镰刀菌的数量,变化趋势与荧光定量PCR检测趋势相似。因此使生防菌快速定殖是提高其对土传病害防治效果的重要因素之一。

Population Dynamics of Trichoderma spp., Bacillus subtillis and Fusarium solani f.sp.cucurbitae in Cucumber Rhizosphere

The biocontrol efficiency of Trichoderma spp. and Bacillus subtilis on cucumber root rot caused by Fusarium solani f. sp. cucurbitae and their quantitative dynamic changes in cucumber rhizosphere soil were monitored. Results showed that application of bio-agents reduced significantly the disease incidence of cucumber root rot and control efficiency reached 100% and 92.5%, 96.71% and 86.76%, 85.35% and 79.24% at 7, 14 and 27 days after treatment with 500×Trichoderma spp. bio-organic fertilizer and 100× B. subtilis, respectively. While the copy numbers from Trichoderma spp. and B. subtilis decreased after 7 days of inoculation from 130787 copys/μL) to 51161 copys/μL, and increased rapidly later maintained up to 295139 copys/μL and 680556 copys/μL from 7 d to 28 d for B. subtillis. The change tendency of Trichoderma spp. was the same as the B. subtilis. On the other hand, the copy numbers of the pathogen, F. solani, in cucumber rhizosphere, increased after 7 days of inoculation from 2.61 copys/μL up to 11.22 copys/μL when treated with B. subtilis and 15.34 copys/μL to 20.98 copys/μLwith Trichoderma spp., respectively. And then, maintained at the high level for a period of time. Thedynamic change of B. subtilis, Trichoderma spp. and F. solani detected with plate dilution method was similar to that with RT-PCR.