Characterization of a pseudomonad‐like bacterium pathogenic for Anthurium species ¹

Abstract

Bacterial isolates were obtained from diseased anthuriums at a number of locations in Trinidad. The biochemical and physiological characteristics of these strains were identical to those of a recently described group of pseudomonad‐like bacteria pathogenic on Anthurium species. These isolates were studied further using chemotaxonomic and molecular techniques to elucidate the true identity of the pathogen. Fatty‐acid profiles showed marked similarities to certain pseudomonads now placed within the genus Acidovorax. In general, major amounts of 16:1 and 16:0 were detected. Significantly, only a single hydroxy fatty acid, 10:0 3‐OH, was found in all strains. The latter characteristic is common for most members of the genera Acidovorax and Comamonas. Isolates could not be unequivocally assigned to any known taxa within these genera. Isolates were also studied by randomly amplified polymorphic DNA analysis (RAPD). Results from this simple method have confirmed the uniqueness of this group whilst establishing its similarity to the genus Acidovorax.

Acidovorax anthurii sp. nov., a new phytopathogenic bacterium which causes bacterial leaf-spot of anthurium.

“…Examination of the raw data from this study has shown that the presence or absence of pentadecenoic acid (15 : 1) is the major qualitative difference between CFBP 3232 T and other A. anthurii. Differences in the fatty acid profiles of strains of the same species have been recorded previously, Stead (1992) found that Burkholderia (Pseudomonas) glumae comprised two distinct populations, similarly in a previous study of A. anthurii strains isolated from diseased anthuriums from Trinidad, isolates were recovered in two distinct clusters (Saddler et al, 1995).…”

“…dieffenbachiae. However, a distinct bacterial disease, the bacterial leafspot, causing only limited damage compared to those due to bacterial blight, has emerged recently in some anthurium farms in the French West Indies and Trinidad (Prior & Rott, 1987 ;Saddler et al, 1995). Following the first observations in restricted areas in Guadeloupe, bacterial leaf-spot was confirmed in Trinidad (Dilbar et al, 1992) and is becoming more widespread.…”

Phylogenetic relationships among members of the Comamonadaceae, and description of Delftia acidovorans (den Dooren de Jong 1926 and Tamaoka et al. 1987) gen. nov., comb. nov.

“…The Anthurium pathogen strain IMI 357678 was most closely related to Acidovorax konjaci, a relationship which was not revealed previously by random-amplified polymorphic DNA analysis (RAPD) (Saddler et al, 1995). Strain IMI 357678 shared a sequence similarity of 98.1 YO with Acidovorax konjaci; this strain appears to be a new species but its taxonomic standing will need to be resolved by DNA-DNA hybridization.…”

“…Within the genus Acidovorax, the validly described species (Acidovorax avenae, Acidovorax konjaci, Acidovorax facilis, Acidovorax temperans, Acidovorax delafieldii), the strain 7087 from activated sludge (Koivula & Hantula, 1997) and the Anthurium pathogen strain IMI 357678 (Saddler et al, 1995) clustered together. The level of the 16s rDNA sequence similarity of the species of Acidovorax and strains 7087 and IMI 357678 ranged from 95.8 to 99340, which revealed that the genus Acidovorax is phylogenetically homogeneous.…”

“…Recently, the causative organism of bacterial leaf spot on Anthurium sp. (Prior & Rott, 1989) was found to belong to the genus Acidovorax (Saddler et al, 1995). However, its relationship to the existing species of Acidovorax is not clear.…”