Bacterial Populations Associated with Rice Seed in the Tropical Environment

Abstract

During the 1995 wet season, harvested rice seed was collected from farmers' fields at different locations in Iloilo, Philippines. Bacterial isolations from crushed seed yielded 428 isolates. The isolates were characterized by BOX-polymerase chain reaction fingerprinting of total genomic DNA and represented 151 fingerprint types (FPT). Most FPTs were found on a single occasion, although matching fingerprints for isolates from different samples also were found. Identifications were made by cellular fatty acid methyl ester analysis and additional use of Biolog GN/GP MicroPlates and API 20E/50CHE systems. The predominant bacteria were Enterobacteriaceae (25%), Bacillus spp. (22%), and Pseu-domonas spp. (14%). Other bacteria regularly present were identified as Xanthomonas spp., Cellulomonas flavigena, and Clavibacter michiganense. Of the total number of isolated bacteria, 4% exhibited in vitro antifungal activity against Rhizoctonia solani or Pyricularia grisea. Two percent of isolates were pathogens identified as Burkholderia glumae and Burkholderia gladioli. Five percent of isolates induced sheath necrosis on only 50 to 90% of inoculated plants and were related to Bacillus pumilus, Paenibacillus spp., Pseudomonas spp., and Pantoea spp.

Identification and determination of characteristics of endophytes from rice plants and their role in biocontrol of bacterial blight caused by Xanthomonas oryzae pv. oryzae

“…Pantoea ananatis from Cambodia, and Pantoea spp. and Pantoea stewartii from the Philippines have been identifi ed as pathogens with diff erent pathogenic potential (Cother et al, 2010;Mano et al, 2006;Mano et al, 2007;Okunishi et al, 2005;Cottyn et al, 2001;Cottyn et al, 2009). Pseudomonas oryzihabitans, Pseudomonas spp.…”

“…Pseudomonas oryzihabitans, Pseudomonas spp. and Cellulomonas fl avigena have been reported as seed saprophytes in irrigated areas with low pathogenic potential trait from the Philippines (Cottyn et al, 2001;Cottyn et al, 2009). Moreover, Pseudomonas fulva has been identifi ed as a pathogen in pepper from China and as a diazotrophic endophyte in rice seeds (Qiang et al, 2017;Verma et al, 2001).…”

Burkholderia glumae en el cultivo de arroz en Costa Rica.

“…La ausencia de ambos operones es responsable de la ocurrencia de cepas avirulentas de B. glumae (Cottyn et al, 2001). El primer operón está constituido por cinco genes (toxABCDE) y es necesario para la biosíntesis de la toxoflavina, mientras que el segundo operón contiene cuatro genes (toxFGHI) que son requeridos para el transporte de la toxoflavina hacia el espacio extracelular.…”

“…De hecho se reporta que es común la presencia de cepas no virulentas en plantas (Cottyn et al, 2001) y en algunas investigaciones se ha recuperado hasta un 5% de cepas de B. glumae no patógenas (Nandakumar et al, 2009).…”

PhytopathogenicBurkholderiaSpecies in Bulb Plants in Bulgaria

“…however, other hosts include onion ("slippery skin"), iris and freesia (25). B. gladioli has also been reported as a pathogen of Dendrobium orchids (26) and rice plants (8). the disease "slippery skin" was first described in Bulgaria as "mealy soft rot of onion" by Vitanov (27)(28)(29)(30).…”