Departamento de Microbiologia, Instituto de Biotecnologia Aplicada a Agropecuária (BIOAGRO), 36570-000, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Can J Microbiol. 2010 May;56(5):359-65. doi: 10.1139/w10-022.
Pseudocercospora griseola (Sacc.) Crous & Braun is a widespread fungal phytopathogen that is responsible for angular leaf spot in the common bean (Phaseolus vulgaris L.). A number of fungal phytopathogens have been shown to harbour mycoviruses, and this possibility was investigated in populations of Pseudocercospora griseola. The total nucleic acid extracts of 61 fungal isolates were subjected to agarose gel electrophoresis. Small fragments (800-4800 bp) could be identified in 42 of the samples. The presence of dsRNA in isolate Ig838 was confirmed by treatment of total nucleic acid with DNase, RNase A, and nuclease S1. Transmission electron microscopy revealed the presence of viral-like particles 40 nm in diameter in the mycelia of 2 fungal isolates, namely 29-3 and Ig838. The transmission of dsRNA by means of conidia was 100% for isolate 29-3, but there was loss of 1-6 fragments of dsRNA in monosporic colonies of isolate Ig848. Cycloheximide treatment failed to inhibit the mycovirus in isolate 29-3, but proved efficient in the elimination of the 2.2, 2.0, 1.8, 1.2 and 1.0 kb fragments in 2 colonies of isolate Ig848. The occurrence of a mycovirus in Pseudocercospora griseola was demonstrated for the first time in the present study.
灰斑拟盘多毛孢（Sacc.）Crous & Braun 是一种广泛存在的真菌植物病原体，可引起普通菜豆（Phaseolus vulgaris L.）的角斑病。已经证明许多真菌植物病原体携带真菌病毒，本研究调查了灰斑拟盘多毛孢种群中是否存在此类病毒。将 61 个真菌分离物的总核酸提取物进行琼脂糖凝胶电泳。在 42 个样本中可以鉴定出小片段（800-4800bp）。通过用 DNase、RNase A 和核酸酶 S1 处理总核酸，证实了分离物 Ig838 中 dsRNA 的存在。透射电子显微镜显示，在 2 个真菌分离物（29-3 和 Ig838）的菌丝体中存在直径为 40nm 的病毒样颗粒。dsRNA 通过分生孢子的传递在分离物 29-3 中为 100%，但在分离物 Ig848 的单孢菌落中，dsRNA 的 1-6 个片段丢失。环已酰亚胺处理未能抑制分离物 29-3 中的真菌病毒，但在消除分离物 Ig848 的 2 个菌落中的 2.2、2.0、1.8、1.2 和 1.0kb 片段方面非常有效。本研究首次证明灰斑拟盘多毛孢中存在真菌病毒。
