摘要
【目的】根际促生菌(plant growth promoting rhizobacteria,PGPR)防控青枯病效果不稳定是目前有益微生物生防应用的瓶颈问题,构建稳定高效拮抗青枯菌的PGPR菌群是生物防控的关键。【方法】以前期筛选到的8株PGPR菌株(112、114、Ba-S、TLZZ、LX4、LX7、Ps-S和VC110)和青枯菌(Ralstonia solanacearum,Rs)为研究对象,在前期获得烟草根系分泌物组成的基础上,采用限菌微系统和生态微孔板结合绿色荧光蛋白标记、定量聚合酶链式反应(quantitative polymerase chain reaction,qPCR)、断棒模型设计等方法,探究PGPR菌群对青枯菌入侵烟草根际的抵御机制,并在田间进行抗病、促生效果验证。【结果】LX4、Ba-S、LX7可以充分利用烟草根系分泌物中的氨基酸、糖类碳源抑制青枯菌生长,LX7和112在所有酸类碳源下均对青枯菌有抑制作用,最高抑菌率分别为40.12%(LX7+乳酸)和35.15%(112+柠檬酸)。Ps-S、112和VC110的基础生态位宽度(basal niche breadth,Bsw)分别比Rs(Bsw=2.56)高41.9%、41.0%和38.1%,Ba-S的基础生态位重叠指数(niche overlap index,NOI)显著比其他PGPR菌株高4.88%–61.76%,与青枯菌存在明显的营养利用性竞争。4株PGPR组成的菌群组合中病情指数平均为27.01%,根际青枯菌数量平均为1.1×10^(4 )CFU/g,显著低于单株和2株PGPR菌群组合,8株PGPR组成菌群处理烟株未发病,根际青枯菌数量平均为3.5×10^(2) CFU/g。由LX4、Ba-S、LX7和VC110构成的菌群组合(菌群组合32)对不同碳源的利用效率显著高于青枯菌,尤其体现在醇类和糖类碳源利用方面,分别是青枯菌的1.62倍和1.41倍。菌群组合32田间防效显著高于其他处理,分别比菌群39(Ba-S、VC110、114和TLZZ)、40(LX4、LX7、VC110和112)和43(Ba-S、VC110、114和112)高27.18%、60.05%和54.80%,菌群32处理的产量和产值相对较好,分别较不施PGPR的对照增加67.50%和73.53%。【结论】可以利用不同PGPR菌株对青枯菌营养竞争或者拮抗竞争
[Objective]The effect of plant growth-promoting rhizobacteria(PGPR)on bacterial wilt is unstable,which poses a challenge to the application of beneficial microorganisms.Thus,developing a stable and efficient PGPR flora against bacterial wilt is the key to the biocontrol.[Methods]The 8 anti-Ralstonia solanacearum(Rs)strains of PGPR(112,114,Ba-S,TLZZ,LX4,LX7,Ps-S,and VC110)that had been screened out by our research group and Rs were studied.Based on the composition of tobacco root exudates,the microbial restriction microsystem,microplate,green fluorescent protein labeling,quantitative PCR,rod model design,and other methods were employed to explore the mechanism of PGPR against Rs in tobacco rhizosphere.In addition,experiment on the disease-resistant and growth-promoting effects was carried out in the field.[Results]LX4,Ba-S,and LX7 can make full use of amino acids and carbohydrates in tobacco root exudates as carbon sources to inhibit the growth of Rs.LX7 and 112 suppressed Rs with all acid carbon sources,and the highest antibacterial rates were 40.12%(LX7+lactic acid)and 35.15%(112+citric acid),respectively.The basal niche breadth(Bsw)of Ps-S,112,and VC110 was 41.9%,41.0%,and 38.1%higher than that of Rs(Bsw=2.56),respectively.The basal niche overlap index(NOI)of Ba-S was 4.88%–61.76%significantly higher than that of any other PGPR strains,and this strain obviously competed with Rs for nutrients.The average disease index was 27.01%and the average count of Rs in tobacco rhizosphere was 1.1×10^(4) CFU/g in the treatments with the combinations of four PGPR strains,which were significantly lower than those in the treatments with one PGPR strain and two strains.The tobacco plants treated with 8 strains of PGPR were free from the wilt,with the average Rs count of 3.5×10^(2) CFU/g.The utilization efficiency of different carbon sources by combination 32(consisting of LX4,Ba-S,LX7 and VC110)was significantly higher than that by Rs and particularly the utilization efficiency of alcohols and carbohydrate by the combinatio
作者
刘艳霞
陶正朋
李想
张恒
朱经伟
王丰
焦剑
王克敏
徐健
汪维维
李寒
LIU Yanxia;TAO Zhengpeng;LI Xiang;ZHANG Heng;ZHU Jingwei;WANG Feng;JIAO Jian;WANG Kemin;XU Jian;WANG Weiwei;LI Han(Guizhou Academy of Tobacco Science,Guiyang 550000,Guizhou,China;College of Tobacco Science,Guizhou University,Guiyang 550000,Guizhou,China;China Tobacco Guizhou Company,Guiyang 550000,Guizhou,China;Zunyi City Company of Guizhou Tobacco Corporation,Zunyi 563000,Guizhou,China)
出处
《微生物学报》
CAS
CSCD
北大核心
2023年第3期1099-1114,共16页
Acta Microbiologica Sinica
基金
国家自然科学基金(31860597)
中国烟草总公司贵州省公司科技项目(201905,2021XM18,2022XM03)
贵州省科技厅院士工作站(黔科合平台人才[2020]4004)。
关键词
根际促生菌
青枯菌
生态位重叠指数
菌群构建
生物防控
plant growth-promoting rhizobacteria(PGPR)
Ralstonia solanacearum
niche overlap index
microflora construction
biocontrol
