Symptomatology of Fusarium oxysporum Causing Pitaya Fusarium Fruit Rot in Taiwan
Other Title
引起臺灣紅龍果鐮孢果腐病Fusarium oxysporum之病徵探討
Journal
台灣農業研究
Journal Volume
75
Journal Issue
1
Start Page
87
End Page
101
ISSN
2790-086X
Date Issued
2026-03-05
Author(s)
Abstract
Fusarium fruit rot is one of the common postharvest diseases of pitaya fruit in Taiwan. Since 2013, infected postharvest fruits were collected, exhibiting symptoms such as light brown patches with transverse stripes, white mycelium on the surface, or water-soaked lesions in severe cases. Green spots and less frequently observed scarring or rot on the pedicels and junctional branches of young fruits were also collected. All isolates obtained from these tissues exhibited morphological characteristics like those of Fusarium oxysporum. Further examination of colony morphology and sporulation patterns, combined with multilocus phylogenetic analyses based on RNA polymerase II second largest subunit (rpb2) and translation elongation factor 1-α (tef1) confirmed that all isolates belonged to F. oxysporum. Through artificial inoculation, symptoms on the postharvest fruits caused by F. oxysporum were confirmed, with symptoms showing a strong correlation with environmental humidity. When inoculation was performed on the surface of field-growing young fruits, green spots appeared after the color transition stage. Interestingly, consistent with the observations in the field, these spots did not progress to typical Fusarium fruit rot as the fruit matured, suggesting that the green spot and fruit rot symptoms may arise from infections occurring at different stages of fruit development. Also, the symptom of scarring and rot on pedicels were confirmed by the inoculation on the growing young fruits. This is the first disease report of the diversified symptoms on pitaya fruits caused by F. oxysporum, which can be attributed to different environment conditions and inoculation stage.
鐮孢果腐病 (Fusarium fruit rot) 為臺灣紅龍果常見的採收後果實病害之一。自 2013 年起，採集罹染鐮孢果腐病的採收後果實，包含果表帶有橫紋或白色菌絲之塊狀褐斑，嚴重者呈水浸狀腐爛；或田間果實表面綠斑、幼果果梗處結痂及連接處腐爛等病徵。病徵經過組織分離後皆可得與 Fusarium oxysporum 形態特徵相似的分離株。進一步觀察菌落與產孢形態，以及利用 RNA polymerase II second largest subunit (rpb2) 與translation elongation factor 1-α (tef1) 等 2 序列片段做多重序列親緣關係分析，確認皆屬 F. oxysporum。透過人工接種採收後果實，確認 F. oxysporum 引起之採後果實病徵，且病徵表現與環境濕度關係性高；接種於田間幼果表面時，接種點於果實轉色期後呈現綠斑，有趣的是，與田間發現的綠斑果實狀況一致，後續果實成熟後不會進展為鐮孢果腐病。亦透過接種田間幼果果梗確認 F. oxysporum 菌株可引起結痂或腐爛。本研究為首篇確認F. oxysporum可引起紅龍果果實多型病徵之報導，並確認其病徵差異與環境條件以及接種時機有關。
Subjects
Pitaya
Postharvest disease
Fusarium fruit rot
Fusarium oxysporum
紅龍果
採後病害
鐮孢果腐病
Publisher
農業部農業試驗所
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
75-1-5.pdf
Size
3.91 MB
Format
Adobe PDF
Checksum
(MD5):1c27e5692a753fa85621ea846386ed93