Anith K N, Nysanth N S, Natarajan C
Department of Agricultural Microbiology, College of Agriculture, Kerala Agricultural University, Thiruvananthapuram, Kerala, India.
Lett Appl Microbiol. 2021 Aug;73(2):229-236. doi: 10.1111/lam.13495. Epub 2021 May 14.
Biological control of plant diseases with antagonistic bacteria is a promising alternative to conventional chemical control strategies. In vitro screening for inhibition of mycelial growth of phytopathogenic fungi by bacterial isolates is the first step in selecting putative bacterial biocontrol agents. Dual culture plate assay is the most common method involved in this first-line selection process. However, it needs independent agar plates to test antagonism by a specific bacterial isolate against each of the fungal phytopathogen. Two modified in vitro antagonism tests are proposed here. Antagonistic activity of a putative biocontrol bacterial strain against four different fungal phytopathogens could be assessed in a single agar plate simultaneously. A comparison of the new methods with conventional dual culture plate assay was also done. The proposed methods are easy to perform and results of antagonism are obtained rapidly. Results of fungal inhibition were qualitatively comparable with that generated through dual culture plate assay. Quantity of resources such as agar medium and plates required for the modified antagonistic assays is several folds less than that required for dual culture plate assay.
利用拮抗细菌对植物病害进行生物防治是传统化学防治策略的一种有前景的替代方法。通过细菌分离物抑制植物病原真菌菌丝生长的体外筛选是选择潜在细菌生物防治剂的第一步。对峙培养平板法是这一首选过程中最常用的方法。然而，它需要独立的琼脂平板来测试特定细菌分离物对每种植物病原真菌的拮抗作用。本文提出了两种改良的体外拮抗试验。在一个琼脂平板上可以同时评估一种潜在生物防治细菌菌株对四种不同植物病原真菌的拮抗活性。还将新方法与传统对峙培养平板法进行了比较。所提出的方法易于操作，能快速获得拮抗结果。真菌抑制结果在定性上与通过对峙培养平板法产生的结果相当。改良拮抗试验所需的琼脂培养基和平板等资源数量比对峙培养平板法所需的少几倍。
