Jiangsu Key Laboratory for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing 210095, China.
Microbiol Res. 2012 Mar 20;167(3):135-43. doi: 10.1016/j.micres.2011.06.002. Epub 2011 Jul 19.
Biological control is an efficient and environmentally friendly way to prevent damping-off disease. Micrographs were used to investigate the ability of Bacillus pumilus (B. pumilus) SQR-N43 to control Rhizoctonia solani (R. solani) Q1 in cucumbers. The root colonization ability of B. pumilus SQR-N43 was analyzed in vivo with a green fluorescent protein (GFP) tag. A pot experiment was performed to assess the in vivo disease-control efficiency of B. pumilus SQR-N43 and its bio-organic fertilizer. Results indicate that B. pumilus SQR-N43 induced hyphal deformation, enlargement of cytoplasmic vacuoles and cytoplasmic leakage in R. solani Q1 mycelia. A biofilm on the root surface was formed when the roots were inoculated with 10(7)-10(8)cells g(-1) of soil of GFP-tagged B. pumilus SQR-N43. In the pot experiment, the biocontrol reduced the concentration of R. solani. In contrast to applications of only B. pumilus SQR-N43 (N treatment), which produced control efficiencies of 23%, control efficiencies of 68% were obtained with applications of a fermented organic fertilizer inoculated with B. pumilus SQR-N43 (BIO treatment). After twenty days of incubation, significant differences in the number of CFUs and the percentage of spores of B. pumilus SQR-N43 were recorded between the N treatment (2.20×10(7)CFU g(-1) of soil and 79%, respectively) and the BIO treatment (1.67×10(8)CFU g(-1) of soil and 52%, respectively). The results indicate that B. pumilus SQR-N43 is a potent antagonist against R. solani Q1. The BIO treatment was more effective than the N treatment because it stabilized the population and increased the active form of the antagonist.
生物防治是一种防治猝倒病的高效、环保的方法。本文利用显微镜观察了短小芽孢杆菌（Bacillus pumilus）SQR-N43 对黄瓜立枯丝核菌（Rhizoctonia solani）Q1 的防治能力。利用绿色荧光蛋白（GFP）标记物对短小芽孢杆菌 SQR-N43 的根际定殖能力进行了体内分析。通过盆栽试验评估了短小芽孢杆菌 SQR-N43 及其生物有机肥的体内防病效果。结果表明，短小芽孢杆菌 SQR-N43 诱导立枯丝核菌 Q1 菌丝变形、细胞质空泡增大和细胞质泄漏。当用 10(7)-10(8)个细胞 g(-1)的土壤接种 GFP 标记的短小芽孢杆菌 SQR-N43 时，在根表面形成生物膜。在盆栽试验中，生物防治降低了立枯丝核菌的浓度。与仅施用短小芽孢杆菌 SQR-N43（N 处理）的 23%的防治效率相比，施用接种短小芽孢杆菌 SQR-N43 的发酵有机肥（BIO 处理）的防治效率达到 68%。培养二十天后，N 处理（土壤中分别为 2.20×10(7)CFU g(-1)和 79%）和 BIO 处理（土壤中分别为 1.67×10(8)CFU g(-1)和 52%）之间的短小芽孢杆菌 SQR-N43 的 CFU 数和孢子百分比有显著差异。结果表明，短小芽孢杆菌 SQR-N43 是立枯丝核菌 Q1 的有效拮抗物。BIO 处理比 N 处理更有效，因为它稳定了种群并增加了拮抗物的活性形式。
