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Bacterial soft rot of aloe caused by Pectobacterium chrysanthemi : a new report from India
Author(s) -
Mandal K.,
Maiti S.
Publication year - 2005
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/j.1365-3059.2005.01193.x
Subject(s) - biology , sucrose , salicin , fructose , bacteria , maltose , mannitol , nutrient agar , food science , lactose , cellobiose , raffinose , xylose , fermentation , microbiology and biotechnology , agar , botany , biochemistry , cellulase , cellulose , genetics
A new leaf rot disease of Aloe vera was observed for the first time in 2000, at the National Research Centre for Medicinal and Aromatic Plants, India. The disease was serious when abundant moisture was available through irrigation and/or rain. The symptoms started as watersoaked lesions at the base of leaves. The rotting progressed very fast and the whole plant died within 2–3 days. As rotting progressed, the leaf epidermis bulged out due to gas formation and the leaf content was converted to a slimy mass, which was eventually released. A bacterium was isolated from the infected tissues. The organism was a nonspore-forming, motile, short rod, and usually single. It produced circular, convex, small (< 1 mm) colonies without pigmentation after 24 h on nutrient agar. The bacterium produced positive reactions to: catalase; levan production; gelatine liquefaction; anaerobic growth; fermentative utilization of glucose and gas formation; utilization and acid production from arabinose, ribose, xylose, galactose, sucrose, fructose, salicin, inositol, mannitol, cellobiose; and lypolytic activity. Negative reactions were found to: Gram staining; oxidase; starch hydrolysis; H 2 S production; acid production from methylα d -glucoside, lactose, sorbitol, maltose, trehalose, dulcitol and adonitol; and production of reducing substance from sucrose. Pathogenicity was confirmed by inoculation of leaves in potted plants or excised leaves with bacterial suspension ( ≈ 6 × 10 6 CFU mL − 1 ) either infiltrated or injected. Characteristic symptoms appeared within 24 h of inoculation. The bacterium was identified as Pectobacterium chrysanthemi on the basis of the above characteristics along with quantitative fatty acid methyl ester analysis and metabolic profiling (Biolog) at CABI Bioscience (IMI 389157). This disease was first reported from the Caribbean island of Aruba (de Laat et al ., 1994) and Korea ( Jin et al ., 1994). This is the first report of the disease from India.