COLLETOTRICHUM GLOEOSPORIOIDES (PENZIG) PENZIG & SACCARDO ニ ヨル グアバ タンソ ビョウ

Abstract

1998年,沖縄県豊見城村で収穫前のグアバ果実に腐敗が発生した。最初,緑色の果実表面に褐色小斑が発生,その後成熟した黄色の果実に茶褐色の病斑が急速に拡大し,果実表皮下に未熟な分生子層が多数形成され,さらに表皮を裂開した成熟分生子層からは円筒形の分生子(大きさ : 8.1～18.8μm×3.5～4.5μm)が豊富に観察された。また得られた分離株を用い接種試験を行った結果,グアバをはじめパパイア,マンゴー果実にも病原性を示した。これらの結果から本病は,Colletotrichum gloeosporioides (Penzig) Penzig & Saccardoによって引き起こされた炭疽病であることが確認された。In 1998, a new disease was found on Guava (Psidium guajava L.) fruits, in Okinawa prefecture, Japan. Small brown spot lesions appeared first on immature green fruits. After the maturation of fruits, dark brown lesion enlarged and developed rapidly on the yellow colored fruits, and bore members of concentrically arranged acervuli with orange conidial masses. A fungus was isolated from these lesions, the acervuli were subepidermal, 80～200μm in diameter and lacked setae. Conidia were aseptate, hyaline, cylindrical, apex obtuse, base truncate, and measured 8.1～18.8×3.5～4.5μm (av. 11.3×4.1μm). Appressoria were clavate or slightly irregular and brown colored and 4.7×6.8μm in size. The causal fungus was identified as Colletotrichum gloeosporioides (Penzig) Penzig & Saccardo. Anthracnose of Guava was proposed as a new disease in Japan