First Report of Sheath Rot of Rice Caused by Pantoea ananatis in Korea

Abstract

Sheath rot symptoms in rice (Oryza sativa) were commonlyobserved during rice growing season in southern part of Korea in2009 and 2010. Symptoms on glumes and stems of rice ranged fromnecrotic spot to brown discoloration. Lesion appearance was notuniform, and the margins were often diffused with an indistinctchlorosis. No water-socking symptom was observed (Fig. 1A). Weisolated bacteria from small pieces (3−5 mm) of infected tissue ofstem or glume. Tissues were surface-sterilized for 30 s in 1%hypochlorite solution followed by rinsing in sterile distilled water.Tissues were macerated using a pipette tip in 100- µl of water in a 1.5ml Ependorf tube. The macerated tissue was left to soak for 10 min,after which 5 µl of liquid suspension were streaked onto Tryptic SoyBroth agar medium (TSA). Representative colonies were purifiedby repeated sub-cultures. Bacterial isolates were stored at −80