Rhizopus oryzae에 의한 복숭아 무름병

Abstract

In July and August 2011, a disease suspected to be Rhizopus soft rot was observed on peach (Prunus persica var. vulgaris) at the Wholesale Market for Agricultural Products, Jinju, Korea. The first symptom of soft rot on peach is a water-soaked appearance of the affected tissue. The infected parts later disintegrated into a mushy mass of disorganized cells followed by rapid softening of the diseased tissue. The lesion on peach was rapidly softened and rotted, then became brown or dark brown. Optimum temperature for mycelial growth of the causal fungus on PDA was 30oC and growth was still apparent at 37oC Sporangiophores were 6~20 μm in diameter. Sporangia were globose and 35~200 μm in size. The color of sporangia was brownish-grey to blackish-grey at maturity. Sporangiospores were sub-globose, brownish- black streaked and 5~10 μm in size. Columella were globose to sub-globose and 85~120 μm in size. On the basis of mycological characteristics, pathogenicity test, and molecular identification, the causal fungus was identified as Rhizopus oryzae Went & Prinsen Geerligs. To our knowledge,this is the first report of soft rot caused by R. oryzae on peach in Korea.