Brown Ring Spot on Leaves of Kiwifruit Caused by Alternaria alternata

Jeong, In Ho; Kim, Gyung Hee; Lim, Myoung Taek; Hur, Jae Seoun; Shin, Jong Sup; Koh, Young Jin

Research in Plant Disease 2008;14(1):68-70.
Published online April 30, 2008.

Alternaria alternata에 의한 참다래 갈색둥근무늬병

정인호, 김경희, 임명택, 허재선, 신종섭, 고영진

Brown Ring Spot on Leaves of Kiwifruit Caused by Alternaria alternata

In Ho Jeong, Gyung Hee Kim, Myoung Taek Lim, Jae Seoun Hur, Jong Sup Shin, Young Jin Koh

Abstract

Brown leaf spots on leaves of kiwifruit(Actinidia deliciosa) were observed at farmers` orchards in Suncheon and Goheung, Jeonnam Province, Korea in June, 2006. They developed to form dark brown ring spots and severely infected leaves resulted in defoliation during the growing season of kiwifruit. Alternaria sp. was isolated from the diseased leaves repeatedly and was identified as Alternaria alternata on the basis of its mycological characteristics on potato dextrose agar and its pathogenicity was confirmed by wound inoculation on healthy leaves of kiwifruit. A. alternata formed gray to dark sooty gray colony and produced numerous conidia on potato dextrose agar. The conidia, commonly in long chains of 5 or more produced on conidiophores, have 3~5 transverse and 1~2 longitudinal septa and mostly ovoid or obclavate in shape and were pale brown golden brown in color. The condia were 16.5~42.1×6.7~19.5 μm in size and conidiophores were 8.6~112.7 μm in length. This is the first report on the brown ring spot on leaves of kiwifruit caused by A. alternata in Korea.

Key Words: Actinidia deliciosa, Alternaria alternata, Dark brown ring spot, Kiwifruit