關鍵詞：番石榴 / 新宿主紀錄 / 柄銹菌屬 / 柄銹菌目 / 銹菌目 | Keywords: guava / new host records / Puccinia / Pucciniales / Uredinales摘要：桃金孃銹病菌（Austropuccinia psidii）於2025年春季在臺灣中部與北部地區，在白千層（Melaleuca leucadendra）、桃金孃（Rhodomyrtus tomentosa）、肯氏蒲桃（Syzygium cumini）、蒲桃（Syzygium jambos）及未定種赤楠屬植物（Syzygium sp.）的葉片上發現，顯示該病原已在臺灣發生突如其來且廣泛的爆發。在白千層與蒲桃的幼枝及萌芽處可見夏孢子堆，並伴隨有萎凋與死亡現象；成年樹木葉片上亦觀察到病斑，而在未定種赤楠屬植物上，幼苗葉片亦有病斑出現。冬孢子僅在桃金孃上觀察到。經由ITS序列鑑定，確認此銹菌為Austropuccinia psidii。Abstract: The myrtle rust Austropuccinia psidii was found on leaves of Melaleuca leucadendra, Rhodomyrtus tomentosa, Syzygium cumini, S. jambos, and Syzygium sp. (all Myrtaceae) in central and northern Taiwan in spring of 2025, indicating a sudden and widespread outbreak in Taiwan. On M. leucadendra and S. jambos, the uredinia were associated with wilt and death of young shoots and suckers. Leaf spots were found on adult trees, and in Syzygium sp. also on seedlings. Teliospores were found only on Rh. tomentosa. ITS rDNA sequences supported the species identification of the rust fungus.