产紫篮状菌的生防潜力及其对土壤微生物群落的调控

产紫篮状菌Q2菌株是一株分离自健康黄瓜根际的有益微生物。本文通过平皿对峙培养、温室盆栽试验和田间试验评估了Q2菌株对4种土传病害的生防潜力及其与土壤熏蒸技术结合对苦瓜枯萎病的防治效果,并通过平皿稀释培养法、高通量技术和定量PCR技术对其防治苦瓜枯萎病及调控土壤微生物群落的机制进行研究。结果表明: 在温室条件下,Q2菌株对苦瓜枯萎病、烟草黑胫病、烟草根黑腐病和马铃薯茎基腐病具有明显的预防效果,对烟草黑胫病和苦瓜枯萎病防治效果分别达到75.3%和63.4%。在苦瓜枯萎病人工病圃中,单一产紫篮状菌Q2制剂对苦瓜枯萎病的防治效果为51.0%,其结合威百亩土壤熏蒸技术在相同试验条件下对枯萎病的防治效果则达到80%以上。威百亩土壤熏蒸显著降低了土壤中苦瓜枯萎病病原菌即尖镰孢菌的丰度,而Q2菌株有效地抑制了尖镰孢菌数量的恢复趋势。施用Q2菌株显著富集了土壤中的青霉菌、芽孢杆菌和Gaiella等有益微生物,抑制了尖镰孢菌的恢复。土壤熏蒸后,施用产紫篮状菌Q2菌株有助于土壤有益微生物菌群的形成,从而抑制尖镰孢菌,实现对苦瓜枯萎病的防治。

Biocontrol potential of Talaromyces purpurogenus and its regulation on soil microbial community

Talaromyces purpurogenus strain Q2 is a kind of beneficial microbe originally separated from the rhizosphere of healthy cucumber. In this study, we evaluated the biocontrol potential of strain Q2 against four soil-borne diseases by plate confrontation culture, potting in the greenhouse. We further estimated the control efficacy of strain Q2 combined metam-sodium fumigation against Fusarium wilt of bitter gourd in the field. The mechanism of strain Q2 controlling bitter gourd wilt and regulating soil microbial community was examined by plate dilution culture, high throughput sequencing and quantitative PCR. The results showed that strain Q2 could efficiently reduce disease incidence of Fusarium wilt of bitter gourd, potato stem canker, black shank of tobacco and black root rot of tobacco in the green house. Its biocontrol efficacy on black shank of tobacco and bitter gourd wilt was 75.3% and 63.4%, respectively. Biocontrol efficacy of strain Q2 on bitter gourd wilt was 51.0% in the artificial disease nursery inoculated pathogen of bitter gourd wilt, while the control efficacy of strain Q2 combined with soil fumigation technology was more than 80% in the same experiment condition. Strain Q2 application and soil fumigation altered soil microbial community composition and recovery trend. Metam-sodium fumigation significantly reduced the abundances of Fusarium oxysporum and causal agent of bitter gourd wilt. Strain Q2 further suppressed the efficient recovery trend of the pathogen. After application of strain Q2, Penicillium was enriched in soil, as well as the beneficial microbes involved in the suppression of F. oxysporum, such as Bacillus and Gaiella. Overall, after soil fumigation, biocontrol efficacy of strain Q2 on soil-borne diseases such as Fusarium wilt could attribute to the formation of beneficial microbial communities in soil and inhibition of strain Q2 on growth and development of F. oxysporum.