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Biological and Morphological Characterization of Xanthomonas campestris Bacteriophages. K. W. Liew, Department of Plant Pathology, University of Hawaii, Honolulu 96822; A. M. Alvarez, Department of Plant Pathology, University of Hawaii, Honolulu 96822. Phytopathology 71:269-273. Accepted for publication 1 July 1980. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-269.

Seven virulent bacteriophages of Xanthomonas campestris isolated from infested soils and seeds in Hawaii were characterized and compared with two phages each from Japan and North Carolina. The phages have hexagonal heads and fall into three morphological classes based on tail structure. Host specificity and morphology of phages OH₂ and OK₂ from Japan are similar to phages HP₁, HP₃, HT₇, and HT_3h from Hawaii. This group of phages has contractile tail sheaths surrounding rigid cores with narrow “neck” regions. Uncontracted tails average 18 × 115 nm and heads measure 55–65 nm in diameter. Hawaiian phages A342 and HXX are morphologically similar to North Carolina phages P_1-3a and P₆ in having noncontractile flexuous tails that average 14 × 120 nm and heads that measure ~55 nm in diameter. Wisconsin phage RR68 has a short wedge-shaped tail 15 nm long. The phages differ in susceptibility to heat and in relative efficiency of plating at different incubation temperatures and were further characterized by the rates of adsorption onto homologous host bacteria and also other parameters measured during the one-step growth experiment.