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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Characterization of Ralstonia solanacearum from Several Solanaceous Plants in Special Territory of Yogyakarta

(Indonesia), Master of Science in Phytopathology (Gadjah Mada University)

Abstract:

 

Fifteen Ralstonia solanacearum isolates of solanaceous crops in Yogyakarta were collected for further investigation on their physiological and biochemical characteristics, and pathogenicity on their respective host. On CPG medium, colonies were white, opaque and fluidal. None of the isolates produced fluorescent pigment on King’s B medium, but all isolates produced melanin pigment on CPG + tyrosin medium. On TCZ medium, fluidal, pink with light red center colonies were produced. Bacteria were gram negative and rod-shaped. All isolates were negative for starch hydrolysis; gelatin liquefaction; arginine; denitrification (not all isolates); levan formation; growth at 13, 15, and 47ºC; growth at pH 4 and 4.5; and growth in 2 percent NaCl medium. All isolates were positive for catalase; oxidase; PHB accumulation; esculin hydrolysis (not all isolates); utilized citrate; growth at 24 , 30, 37, and 41ºC (not all isolates); growth at pH 5, 6, 7, 8.5 and 10; and growth in 0.5 and 1 percent NaCl medium. Some of these isolates exhibited growth in 1.5 percent NaCl medium. All isolates utilized sources of carbon from glucose, lactose, maltose cellobiose, trehalose, mannitol, dulcitol, and sorbitol except To1 and Tb1 did not utilize lactose and maltose. Two isolates To1 and Tb1 could not be grouped into biovar I, II, III, IV, and V but 13 isolates were grouped into biovar III. Hypersensitivity test in tobacco indicated that all isolates showed chlorosis symptom on the injected tissue during 18-24 hours period. Leaf wilted during a week period except Lb1, Lb3, and To2. Pathogenicity test on their respective hosts showed that Tr8 and Tr1, eggplant isolates from Bantul, and Tr5 from Kulonprogo were most virulent based on their shortest incubation period and highest disease index. Host range test showed that the most virulent isolate (Tr8) belonged to race 1.