Bacterial Canker of Grapevine in Roraima, Brazil

Cancro-bacteriano da videira em Roraima

PHYTOPATHOLOGICAL NOTES NOTAS FITOPATOLÓGICAS

Bacterial Canker of Grapevine in Roraima, Brazil

Cancro-bacteriano da videira em Roraima

Bernardo A. Halfeld-Vieira; Kátia de Lima Nechet

Embrapa Roraima, Cx. Postal 133, CEP 69301-970, Boa Vista, RR; e-mail: [e-mail]

RESUMO

Este é o primeiro relato de Xanthomonas campestris pv. viticola causando cancro-bacteriano da videira (Vitis vinifera) no Estado de Roraima, Brasil.

The bacterial canker of grapevine (Vitis vinifera L.), caused by Xanthomonas campestris pv. viticola Nayudu (Dye), is a quarentenary disease officially restricted in Brazil to the states of Bahia, Pernambuco, Piauí and Ceará. The disease was described for the first time in India (Nayudu, Phytopathologische Zeitschrift 73:183. 1972) and reported in Brazil in 1998 at Petrolina, PE (Malavolta Jr. et al., Summa Phytopathologica 25:262. 1999). In July 2006, the Plant Pathology Laboratory at Embrapa Roraima received samples from grapevine plantations established in Boa Vista, RR, with stem canker and leaf necrosis symptoms. An intense exudation was observed when these materials were examined under the light microscope. Upon isolating the bacteria it was observed that a permanent association exists between the bacteria able to incite a typical hypersensitive reaction in tomato cv. Santa Clara and tobacco plants only 48 h after infiltration. The bacteria presented the following characteristics: aerobic growth with white colonies, convex, mucoid, no fluorescent pigment production in culture media and gram-negative reaction. Positive results were obtained for esculin and starch hydrolysis, acid from trehalose, glucose, celobiose, melibiose and arabinose and weakly positive for glycerol. Negative results were obtained for oxidase, urease, use of asparagine as sole carbon and nitrogen source, and acid production from dulcitol. To perform Koch’s postulates, grapevine plants var. Italia and Niagara Rosada were inoculated by spraying a suspension of bacterial cells previously adjusted to 10⁷ cfu.mL^-1. In stems, a 50 µL aliquot of the suspension was deposited on a wound caused by a micropipette tip. Plants were transferred to a humid chamber for 48 h. After that, plants were moved to a greenhouse. Leaf spots were observed after 12 days in var. Italia and 18 days in var. Niagara Rosada plants. Necrosis and initial canker on stems were observed 20 days after inoculation, re-isolating the pathogen. These characteristics allowed the identification of the bacteria Xanthomonas campestris pv. viticola as the causal agent of the disease (Schaad et al., Laboratory guide for identification of plant pathogenic bacteria. 3 ed. 2001; Nascimento & Mariano, Ciência Rural. 34:301. 2004). In Boa Vista city, grapevine plantations have been established using propagative material from Petrolina, and the disease must have been introduced in this way. This is the first report of bacterial canker of grapevine in Roraima State.

Aceito para publicação em 18/12/2006

Autor para correspondência: Bernardo A. Halfeld-Vieira

Publication Dates

• Publication in this collection
  15 Mar 2007
• Date of issue
  Dec 2006