Characteristics of Bacteriophage of Xanthomonas campestris pv. phaseoli (Smith) Dye in Thailand .

Abstract

The characteristics of bacteriophage of Xanthomonas campestris pv. phaseoli (Smith) Dye 1978, causing bacterial pustule of soybean, isolated from infected soybean leaves and soil beneath the diseased plants were studied. Three plaque types with large (2.5-3.0 mm in diameter), medium (1.5-2.0 mm) and small (less than 1.5 mm) sizes were observed. After the purification and multiplication of each plaque, morphological investigation of the phage through transmission electron microscope showed only one phage type with typical character of polyhedral head and rod – shaped tail. Head and tail of the phage were elongated with 70 x 55 nm and 15 x 18 nm respectively. The effects of temperature, pH condition and alcohol solution on inactivation point of phage were also investigated. The results showed that the phage was completely inactivated within 10 minutes after the treatment under 60ºC temperature, 7.0 pH and 90% ethyl alcohol solution.