A simple inhibition coefficient for quantifying potency of biocontrol agents against plant-pathogenic fungi
A simple inhibition coefficient for quantifying potency of biocontrol agents against plant-pathogenic fungi
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DOI：
10.1016/j.biocontrol.2014.11.006
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发表时间：
2015-02-01
影响因子：
4.2
通讯作者：
Hallsworth, John E.
中科院分区：
文献类型：
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作者：
Cray, Jonathan A.;Houghton, Jonathan D. R.;Hallsworth, John E.
微生物的相互作用依赖于一系列生物和环境变量，并且是动态的和不可预测的。为了某些目的，在规定的条件下，仍有必要评估微生物的抑制效果，例如那些有可能作为生防剂的微生物。我们选择了六种在系统发育上不同的微生物来确定它们抑制子囊菌蓝镰刀菌的能力，蓝镰刀菌是一种土传马铃薯块茎的病原体，会导致贮藏病害干腐病。因此，相互作用分析是在固体介质上进行的，其中菌落发展被量化(真菌病原体和潜在的控制剂)。影响和指示抑制效果的关键参数被确定为：(I)在与生防剂接触之前和(Ii)是否/一旦与生防剂建立了联系(即在混合培养区)，以及(Iii)真菌菌丝体所走的最终距离。很明显，真菌抑制区与真菌菌落发育程度的总体下降之间没有相关性。设计了一个抑制系数，该系数综合了远端抑制真菌生长速率、生防剂附近阻止菌丝发育和混合培养区抑制植物病原菌生长速率(比例为2：2：1)的潜在贡献。枯草芽孢杆菌(QST 713)为84.2，芽孢杆菌为74.0。(JC12GB42)，异常毕赤酵母(J121)为30.7，聚集型泛菌(JC12GB34)为19.3，泛菌(Pantoea)为13.9。(S09：T：12)，以及细菌菌株(JC12GB54)的-21.9(表明促进真菌生长)。这一理论上最大的抑制系数为100，与蓝霉菌落发育的程度(即面积，以厘米(2)为单位)和这些生防剂以前对镰刀菌和其他真菌的测定是一致的。这些发现涉及自然生态系统的动态和内在复杂性，以及在特定条件下调整模型使用的必要性。(C)2014 Elsevier Inc.保留所有权利。
Microbial interactions depend on a range of biotic and environmental variables, and are both dynamic and unpredictable. For some purposes, and under defined conditions, it is nevertheless imperative to evaluate the inhibitory efficacy of microbes, such as those with potential as biocontrol agents. We selected six, phylogenetically diverse microbes to determine their ability to inhibit the ascomycete Fusarium coeruleum, a soil-dwelling pathogen of potato tubers that causes the storage disease dry rot. Interaction assays, where colony development was quantified (for both fungal pathogen and potential control agents), were therefore carried out on solid media. The key parameters that contributed to, and were indicative of, inhibitory efficacy were identified as: fungal growth-rates (i) prior to contact with the biocontrol agent and (ii) if/once contact with the biocontrol agent was established (i.e. in the zone of mixed culture), and (iii) the ultimate distance traveled by the fungal mycelium. It was clear that there was no correlation between zones of fungal inhibition and the overall reduction in the extent of fungal colony development. An inhibition coefficient was devised which incorporated the potential contributions of distal inhibition of fungal growth-rate; prevention of mycelium development in the vicinity of the biocontrol agent; and ability to inhibit plant-pathogen growth-rate in the zone of mixed culture (in a ratio of 2: 2: 1). The values derived were 84.2 for Bacillus subtilis (QST 713), 74.0 for Bacillus sp. (JC12GB42), 30.7 for Pichia anomala (J121), 19.3 for Pantoea agglomerans (JC12GB34), 13.9 for Pantoea sp. (S09: T: 12), and -21.9 (indicating a promotion of fungal growth) for bacterial strain (JC12GB54). This inhibition coefficient, with a theoretical maximum of 100, was consistent with the extent of F. coeruleum-colony development (i.e. area, in cm(2)) and assays of these biocontrol agents carried out previously against Fusarium spp., and other fungi. These findings are discussed in relation to the dynamics and inherent complexity of natural ecosystems, and the need to adapt models for use under specific sets of conditions. (C) 2014 Elsevier Inc. All rights reserved.