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ARS Home » Northeast Area » Frederick, Maryland » Foreign Disease-Weed Science Research » Research » Publications at this Location » Publication #35807

Title: A SEMISELECTIVE MEDIUM FOR THE ISOLATION OF PSEUDOMONAS GLUMAE FROM RICE SEEDS

Author
item KIM H M - CHONBUK NAT UNIV.,KOREA
item SONG W Y - CHONBUK NAT UNIV.,KOREA
item SCHAAD N W - 1920-05-00

Submitted to: Korean Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/1993
Publication Date: N/A
Citation: N/A

Interpretive Summary: Bacterial grain rot of rice, caused by Pseudomonas glumae, has not been reported in the U.S. This seedborne disease is becoming one of the most serious diseases of rice worldwide. The disease affects seedlings, mature plants, and storage grain. To be able to detect contaminated rice seeds, a semiselective medium and seed assay was developed. The defined agar medium resulted in a 84% recovery of 10 strains of the pathogen, in comparison to the standard KB plating medium. The number of saprophytes found on rice seeds was reduced by 90% by PG medium in comparison to KB medium. The medium should be helpful for screening foreign germplasm for this potentially damaging rice pathogen

Technical Abstract: A semiselective agar medium (PG) was developed for the isolation of bacterial grain rot pathogen, Pseudomonas glumae from rice seeds. The medium contained KH2PO4 1.3 g, Na2 HPO4 1.2 g, MgSO4 . 7H2O 0.25 g, ammonium tartrate l.O g, galactose 1O.O g, 1% nitrofurantoin 1.5 ml, 0.1% methylene blue 2.0 ml, cycloheximide 100 mg and agar 15.0 g per liter. Colonies of P. glumae were 1-1.5 mm in diameter, smooth, round, blue (lighter margin) and convex 10 days after incubation at 25 C. The recovery of 10 isolates of P. glumae including ATCC 33617 on the PG medium ranged from 73% to 96% (mean 84.2%) in comparison to King's B (KB) medium. The number of saprophytic bacteria from rice seeds on PG medium was reduced to 89.4% of that on KB medium. The recovery of P. glumae from inoculated rice seeds on PG medium ranged from 75% to 100% (mean 86.4%) of that on KB medium