Balogh B, Jones J B, Momol M T, Olson S M, Obradovic A, King P, Jackson L E
Department of Plant Pathology, University of Florida, Gainesville 32611.
North Florida Research and Education Center, University of Florida, Quincy 32351.
Plant Dis. 2003 Aug;87(8):949-954. doi: 10.1094/PDIS.2003.87.8.949.
Bacteriophages are currently used as an alternative method for controlling bacterial spot disease on tomato incited by Xanthomonas campestris pv. vesicatoria. However, the efficacy of phage is greatly reduced due to its short residual activity on plant foliage. Three formulations that significantly increased phage longevity on the plant surface were tested in field and greenhouse trials: (i) PCF, 0.5% pregelatinized corn flour (PCF) + 0.5% sucrose; (ii) Casecrete, 0.5% Casecrete NH-400 + 0.5% sucrose + 0.25% PCF; and (iii) skim milk, 0.75% powdered skim milk + 0.5% sucrose. In greenhouse experiments, the nonformulated, PCF-, Casecrete-, and skim milk-formulated phage mixtures reduced disease severity on plants compared with the control by 1, 30, 51, and 62%, respectively. In three consecutive field trials, nonformulated phage caused 15, 20, and 9% reduction in disease on treated plants compared with untreated control plants, whereas plants treated with PCF- and Casecrete-formulated phage had 27, 32, and 12% and 30, 43, and 24% disease reduction, respectively. Plants receiving copper-mancozeb treatments were included in two field trials and had a 20% decrease in disease in the first trial and a 13% increase in the second one. Skim milk-formulated phage was tested only once and caused an 18% disease reduction. PCF-formulated phage was more effective when applied in the evening than in the morning, reducing disease on plants by 27 and 13%, respectively. The Casecrete-formulated phage populations were over 1,000-fold higher than the nonformulated phage populations 36 h after phage application.
噬菌体目前被用作控制由野油菜黄单胞菌番茄致病变种引起的番茄细菌性斑点病的一种替代方法。然而，由于噬菌体在植物叶片上的残留活性较短，其功效大大降低。在田间和温室试验中测试了三种能显著提高噬菌体在植物表面存活时间的配方：（i）PCF，0.5%预糊化玉米粉（PCF）+0.5%蔗糖；（ii）Casecrete，0.5%Casecrete NH - 400+0.5%蔗糖+0.25%PCF；以及（iii）脱脂乳，0.75%脱脂奶粉+0.5%蔗糖。在温室试验中，与对照相比，未配方化的、PCF -、Casecrete -和脱脂乳配方化的噬菌体混合物分别使植物病害严重程度降低了1%、30%、51%和62%。在连续三次田间试验中，与未处理的对照植株相比，未配方化的噬菌体使处理过的植株病害分别降低了15%、20%和9%，而用PCF -和Casecrete -配方化的噬菌体处理的植株病害分别降低了27%、32%和12%以及30%、43%和24%。接受铜 - 代森锰锌处理的植株被纳入两次田间试验，第一次试验病害降低了20%，第二次试验病害增加了13%。脱脂乳配方化的噬菌体仅测试了一次，使病害降低了18%。PCF -配方化的噬菌体在傍晚施用时比早晨施用更有效，分别使植物病害降低了27%和13%。在噬菌体施用36小时后，Casecrete -配方化的噬菌体数量比未配方化的噬菌体数量高出1000倍以上。
