Phytopathology Unit, Department of Plant Protection and Environment, Ecole Nationale d'Agriculture de Meknès, Km10, Rte Haj Kaddour, BP S/40, Meknès 50001, Morocco; Laboratory of Plant Biotechnology and Molecular Biology, Moulay Ismail University, Faculty of Sciences, BP 11201, Ave Zitoune, Meknes, Morocco.
Laboratory of Plant Biotechnology and Molecular Biology, Moulay Ismail University, Faculty of Sciences, BP 11201, Ave Zitoune, Meknes, Morocco.
Microb Pathog. 2018 Apr;117:7-15. doi: 10.1016/j.micpath.2018.02.011. Epub 2018 Feb 8.
The effectiveness of antagonistic bacteria to control Erwinia amylovora was evaluated under in vitro and field conditions. Among 61 bacteria isolated from soil and flowers of fire blight host plants of different Moroccan areas, 20 bacterial isolates showed higher antagonistic activity against the pathogen during agar-diffusion-test, attached blossoms assay and in a bioassay on immature pear fruits. Effective isolates were identified by using biochemical tests and 16 S rRNA genes sequencing. These isolates were grouped into the following genera: Alcaligenes (ACBC1), Pantoea (ACBC2, ACBP1, and ACBP2), Serratia (HC4), Brevibacterium (SF3, SF4, SF7, and SF15), Pseudomonas (SP9), and Bacillus (CPa12, CPa2, HF6, JB2, LMR2, SF14, SF16, SP10, SP13, and SP18). Furthermore, isolates were reported in the NCBI nucleotide sequence database (Genbank) under the accession numbers from KY357285 to KY357304. A 2-year field trials consisted of spray treatments with different bacterial antagonists was conducted on the susceptible apple cultivars 'Gala', 'Golden Parsi' and 'Golden Smoothee'. Their efficacies were evaluated 15 days post-inoculation on detached blossoms and were ranged from 54.6 to 95.0% for 11 strains, most of them were slightly better or better than that obtained with commercial bacterial strains P10c (66%) and QST713 (63%). In field trials, the most effective were P. agglomerans ACBP2, B. amyloliquefaciens LMR2, B. halotolerans (SF3 and SF4), and B. mojarvensis SF16. In addition, effective bacterial isolates did not show the pathogenicity signs towards plant tissue and are, therefore, considered as potential candidates to be integrated in actives ingredients of microbial formulation for the effective control of Fire Blight.
在体外和田间条件下评估了拮抗菌对果胶杆菌的控制效果。从不同摩洛哥地区火疫病寄主植物的土壤和花朵中分离出 61 株细菌，其中 20 株在琼脂扩散试验、附着花朵试验和未成熟梨果实生物测定中对病原菌表现出较高的拮抗活性。采用生化试验和 16S rRNA 基因测序对有效分离物进行鉴定。这些分离物被分为以下属：产碱菌（ACBC1）、泛菌（ACBC2、ACBP1 和 ACBP2）、沙雷氏菌（HC4）、短杆菌（SF3、SF4、SF7 和 SF15）、假单胞菌（SP9）和芽孢杆菌（CPa12、CPa2、HF6、JB2、LMR2、SF14、SF16、SP10、SP13 和 SP18）。此外，这些分离物已在 NCBI 核苷酸序列数据库（Genbank）中报道，登录号为 KY357285 至 KY357304。在易感苹果品种 'Gala'、'Golden Parsi' 和 'Golden Smoothee' 上进行了为期 2 年的田间试验，包括不同细菌拮抗菌的喷雾处理。在接种后 15 天，对离体花朵进行了功效评估，11 株菌的防治效果在 54.6%至 95.0%之间，其中大多数比商业菌株 P10c（66%）和 QST713（63%）的防治效果略好或更好。在田间试验中，最有效的是 P. agglomerans ACBP2、B. amyloliquefaciens LMR2、B. halotolerans（SF3 和 SF4）和 B. mojarvensis SF16。此外，有效分离物对植物组织没有表现出致病性，因此被认为是潜在的候选物，可以整合到微生物制剂的有效成分中，以有效控制火疫病。
