Abstract The cultivated rose (Rosa × hybrida) is the most important plant species in the cut flower industry worldwide. In Brazil, rose plantations are said to be frequently attacked by a dieback disease of uncertain etiology. A severe rose dieback outbreak was detected and closely observed in Vicosa (state of Minas Gerais, Brazil). The disease was particularly severe on the cultivar ‘Gran Gala’. A fungus with typical characteristics of the asexual state of Diaporthe spp. was regularly associated to necrotic tissues and isolated in pure culture. Morphology of the fungus was examined and described and DNA was extracted for molecular studies. Phylogenetic analysis inferred from combined dataset of the internal transcribed spacer ribosomal DNA (ITS), partial calmodulin gene (CAL) and partial translation elongation factor 1-α (TEF1) along with morphological characterization, indicated that the fungus causing dieback disease of Rosa × hybrida is a new species of Diaporthe. This is described herein as Diaporthe rosiphthora sp. nov. Its pathogenicity to Rosa × hybrida was evaluated and inoculations on additional selected rose cultivars indicated that, besides ‘Grand Gala’, another important commercial cultivar (‘Saltinho’) is susceptible. Cultivars ‘Greta’ and ‘Principe Negro’, were also susceptible, though less so than ‘Grand Gala’ and ‘Saltinho’. Diaporthe rosiphthora is a novel addition to the numerous fungi associated rose dieback.

中文翻译：

---

Diaporthe rosiphthora sp. 十一月：又一种玫瑰枯萎真菌

摘要 栽培玫瑰（Rosa × hybrida）是全球切花业中最重要的植物品种。在巴西，据说玫瑰种植园经常受到病因不明的枯死病的侵袭。在维科萨（巴西米纳斯吉拉斯州）发现并密切观察到严重的玫瑰枯萎病爆发。该病害在栽培品种“Gran Gala”上尤为严重。一种具有 Diaporthe spp 无性状态的典型特征的真菌。经常与坏死组织相关联并在纯培养中分离。检查和描述了真菌的形态，并提取了 DNA 用于分子研究。从内部转录间隔核糖体 DNA (ITS) 的组合数据集推断出的系统发育分析，部分钙调蛋白基因（CAL）和部分翻译延伸因子 1-α（TEF1）以及形态特征表明引起 Rosa × hybrida 枯死病的真菌是 Diaporthe 的一个新物种。这在本文中被描述为 Diaporthe rosiphthora sp。十一月 评估了其对 Rosa × hybrida 的致病性，并在其他选定的玫瑰品种上接种表明，除了“Grand Gala”之外，另一个重要的商业品种（“Saltinho”）也易感。栽培品种“Greta”和“Principe Negro”也易感，但不如“Grand Gala”和“Saltinho”。Diaporthe rosiphthora 是众多与玫瑰枯死相关的真菌的新成员。这在本文中被描述为 Diaporthe rosiphthora sp。十一月 评估了其对 Rosa × hybrida 的致病性，并在其他选定的玫瑰品种上接种表明，除了“Grand Gala”，另一个重要的商业品种（“Saltinho”）也易感。栽培品种“Greta”和“Principe Negro”也易感，但不如“Grand Gala”和“Saltinho”。Diaporthe rosiphthora 是众多与玫瑰枯死相关的真菌的新成员。这在本文中被描述为 Diaporthe rosiphthora sp。十一月 评估了其对 Rosa × hybrida 的致病性，并在其他选定的玫瑰品种上接种表明，除了“Grand Gala”之外，另一个重要的商业品种（“Saltinho”）也易感。栽培品种“Greta”和“Principe Negro”也易感，但不如“Grand Gala”和“Saltinho”。Diaporthe rosiphthora 是众多与玫瑰枯死相关的真菌的新成员。