生防菌剂多黏类芽胞杆菌对辣椒根际土壤细菌群落的影响

多黏类芽胞杆菌对辣椒疫病有较好的防治效果,本文重点研究了其对辣椒根际细菌微生物的影响。收集了109 cfu/g多黏类芽胞杆菌WP、25%嘧菌酯SC、68%精甲霜·锰锌WG及对照处理后的辣椒根际细菌,通过高通量测序分析了根际细菌种群多样性和群落结构。多黏类芽胞杆菌处理后的辣椒根际细菌多样性最高,化学药剂处理后的辣椒根际细菌多样性也均高于对照。通过分析高通量测序结果,发现辣椒根际细菌包括变形菌门Proteobacteria、奇古菌门Thaumarchaeota、酸杆菌门Acidobacteria、绿弯菌门Chloroflexi、放线菌门Actinobacteria等13个门。变形菌门的丰度在对照(JD)中高达70.65%,而在嘧菌酯(JA)、精甲霜·锰锌(JB)和多黏类芽胞杆菌(JC)的处理中分别降至24.41%、25.64%和34.95%,但仍然是各处理的优势菌群。在化学药剂和多黏类芽胞杆菌的3种处理中酸杆菌门和绿弯菌门菌群的丰度远高于对照,特别是奇古菌门菌在化学药剂处理中的丰度极显著高于多黏类芽胞杆菌和对照处理。经多黏类芽胞杆菌处理后发现芽单胞菌门和芽单胞菌属远高于对照,分别为7.35%(JC)、0.11%(JD)。研究结果表明:施用多黏类芽胞杆菌不仅可以有效防治辣椒疫病,还可以改变辣椒根际土壤微生物区系,提高土壤中细菌种群的多样性。

Effects of the biocontrol agent Bacillus polymyxa on the bacterialcommunity in the rhizosphere of pepper

Bacillus polymyxa showed high activity in controlling pepper blight. The effect of the strain on bacterial microbes in the rhizosphere of pepper was studied. The rhizosphere bacteria of pepper treated by B. polymyxa 109 cfu/g WP, azoxystrobin 25% SC, metalaxyl-M· mancozeb 68% WG and the control were collected, and the diversity and community structure of the rhizosphere bacterial population were analyzed by Illumina Miseq sequencing technology. The diversity of rhizosphere bacteria of the pepper treated with B. polymyxa was the highest, and the diversity of rhizosphere bacteria of the pepper treated with chemical agents was also higher than that of the control. The bacterial populations included 13 phyla such as Proteobacteria, Thaumarchaeota, Acidobacteria, Chloroflexi and Actinobacteria. Proteobacteria was the most dominant phylum. The abundance of Proteobacteria was as high as 70.65% in the control (JD), but decreased in the treatments of azoxystrobin (JA), Metalaxyl-M mancozeb WG (JB) and B. polymyxa (JC), which was 24.41%, 25.64% and 34.95%, respectively. In the three treatments of chemical agent and B. polymyxa, the abundances of Acidobacteria and Chloroflexi were much higher than that of the control. In particular, the abundance of Thaumarchaeota in the treatment with chemical agent was extremely higher than that with B. polymyxa and the control. After treatment with B. polymyxa, the abundance of Gemmatimonadetes was 7.35% higher than that of the control. B. polymyxa as a biological pesticide can improve bacterial species abundance in plant rhizosphere soils and make a great contribution to the prevention of Phytophthora blight.