In vitro antagonists of Rhizoctonia solani tested on lettuce: rhizosphere competence, biocontrol efficiency and rhizosphere microbial community response
In vitro antagonists of Rhizoctonia solani tested on lettuce: rhizosphere competence, biocontrol efficiency and rhizosphere microbial community response
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DOI：
10.1111/j.1574-6941.2009.00685.x
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发表时间：
2009-07-01
影响因子：
4.2
通讯作者：
Smalla, Kornelia
中科院分区：
文献类型：
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作者：
Adesina, Modupe F.;Grosch, Rita;Smalla, Kornelia
将接种的莴苣种子播种到非无菌土壤中4周后，测定了15种离体立枯丝核菌拮抗菌的根际竞争力。根据选择平板法测定的定殖能力，选择8个菌株进行生长室试验，测定其对红曲霉根腐病的防治效果。生菜上的索拉尼。虽然在第一个实验中，所有的拮抗菌定殖生菜根际的CFU计数超过2 × 10（6）g（-1）的根鲜重，只有四个菌株显着降低疾病的严重程度。在随后涉及这四种拮抗剂的实验中，只有杰氏假单胞菌RU 47显示出有效和一致的疾病抑制。平板计数和变性梯度凝胶电泳（DGGE）指纹的假单胞菌特异性gacA基因从总社区DNA扩增证实，RU 47建立作为接种生菜植物根际的优势假单胞菌种群。此外，DGGE指纹图谱显示，R。solani AG 1-IB接种严重影响莴苣根际的细菌和真菌群落结构，并且这些影响在RU 47存在下不太明显。尽管RU 47的确切拮抗机制和生态学还有待进一步研究，但我们的研究结果表明，RU 47是一种很有前途的防治莴苣底腐病的药剂。
The rhizosphere competence of 15 in vitro antagonists of Rhizoctonia solani was determined 4 weeks after sowing inoculated lettuce seeds into nonsterile soil. Based on the colonization ability determined by selective plating, eight strains were selected for growth chamber experiments to determine their efficacy in controlling bottom rot caused by R. solani on lettuce. Although in the first experiment all antagonists colonized the rhizosphere of lettuce with CFU counts above 2 x 10(6) g(-1) of root fresh weight, only four isolates significantly reduced disease severity. In subsequent experiments involving these four antagonists, only Pseudomonas jessenii RU47 showed effective and consistent disease suppression. Plate counts and denaturing gradient gel electrophoresis (DGGE) fingerprints of Pseudomonas-specific gacA genes amplified from total community DNA confirmed that RU47 established as the dominant Pseudomonas population in the rhizosphere of inoculated lettuce plants. Furthermore, the DGGE fingerprint revealed that R. solani AG1-IB inoculation severely affected the bacterial and fungal community structure in the rhizosphere of lettuce and that these effects were much less pronounced in the presence of RU47. Although the exact mechanism of antagonistic activity and the ecology of RU47 remain to be further explored, our results suggest that RU47 is a promising agent to control bottom rot of lettuce.