Phytopathology. 1998 Jun;88(6):506-13. doi: 10.1094/PHYTO.1998.88.6.506.
The influence of inoculum preparation on the establishment of bacterial antagonists that suppress fire blight and Erwinia amylovora on blossoms was evaluated. Aqueous suspensions of Pseudomonas fluorescens A506, E. herbicola C9-1R, or E. amylovora 153N were prepared from cells harvested from the surface of an agar medium or from cells that were lyophilized after culture under similar conditions. Bacterial suspensions (1 x 10(8) CFU/ml) were sprayed on pear and apple trees at 50% bloom near midday. The incidence of recovery (proportion of blossoms containing detectable populations) and the population sizes of the bacteria on individual blossoms with detectable populations were followed over a period of several days. Fluorescent microspheres (1 mum in diameter) were added to sprays at a concentration of 1 x 10(7) microspheres per ml to mark blossoms that were open during application of bacteria. After dilution-plating, the stigmas and styles of each blossom were examined for the presence of microspheres with an epifluorescence microscope. In three of five trials, bacteria applied as suspensions of lyophilized cells were recovered from a greater proportion of blossoms than bacterial cells harvested directly from culture media. Every blossom harvested within 6 days after spraying had microspheres present on the surfaces of the styles and stigmas; thus, lack of establishment of detectable populations, rather than escape of blossoms from spray inoculation, accounted for the differences in proportion of blossoms colonized by the different preparations of bacteria. The use of lyophilized cells in field trials decreased variability in the establishment of bacteria on blossoms.
研究了接种物准备对抑制火疫病和韧皮部杆菌的细菌拮抗剂在花朵上定殖的影响。从琼脂培养基表面收获的细胞或在类似条件下培养后冷冻干燥的细胞中制备出荧光假单胞菌 A506、E. herbicola C9-1R 或 E. amylovora 153N 的水悬浮液。将细菌悬浮液（1x10(8)CFU/ml）在中午接近 50%开花时喷洒在梨树和苹果树上。在几天的时间里，跟踪了可检测到群体的花朵的回收率（包含可检测到的群体的花朵比例）和个体花朵上细菌的种群大小。将直径为 1 µm 的荧光微球以 1x10(7)微球/ml 的浓度添加到喷雾中，以标记在细菌应用期间开放的花朵。稀释平板后，用荧光显微镜检查每个花朵的柱头和花柱上是否存在微球。在五次试验中的三次中，从冷冻干燥细胞悬浮液中应用的细菌从更多比例的花朵中回收，而直接从培养基中收获的细菌细胞则更少。在喷洒后 6 天内收获的每一朵花都在花柱和柱头表面存在微球；因此，缺乏可检测到的群体的建立，而不是花朵逃避喷雾接种，解释了不同细菌制剂处理的花朵定殖比例的差异。在田间试验中使用冷冻干燥细胞降低了细菌在花朵上定殖的可变性。
