臺灣胡瓜萎凋病菌生理分化型之驗證

Identification of the Fusarium oxysporum formae speciales of Cucumber in Taiwan

王照仁(Chao-Jen Wang) ； 黃明進(Min-Jing Huang) ； 陳任芳(Jen-Fang Chen) ； 鍾文鑫(Wen-Hsin Chung) ； 林益昇(Yi-Sheng Lin)

《臺中區農業改良場研究彙報》 143期 (2019/06) Pp. 75-90

摘要

危害胡瓜的尖鐮胞菌（Fusarium oxysporum）有兩個生理分化型，分別是引起萎凋病的F. oxysporum f. sp. Cucumerinum（Foc）和引起根腐與莖腐病的F. oxysporum f. sp. radicis-Cucumerinum（Forc）。為鑑定臺灣胡瓜萎凋病菌屬於哪一種分化型，本研究比較臺灣產胡瓜萎凋病菌菌株與Foc標準菌株（ATCC16416）於病徵、寄主範圍及最適發病溫度之差異性。結果顯示利用土壤混菌法接種胡瓜苗，除ATCC16416，其餘臺灣產菌株均會造成根腐與莖腐的病徵。在寄主範圍測試結果指出，菌株Foc151可感染胡瓜、洋香瓜、香瓜及西瓜，但ATCC16416與Foc100只能感染前三者，不會感染西瓜。而最適發病溫度試驗結果顯示，菌株Foc100與Foc829在17和28℃條件下均會使胡瓜發病，其餘臺灣產供試菌株與ATCC16416均在28℃為最適發病溫度。利用12個Foc與Forc之VCG標準菌株來鑑定臺灣產胡瓜萎凋病菌之營養菌絲親合群（vegetative compatibility group, VCG），證實只有1個菌株（Foc100）是屬於Foc中VCG 0180的一群。另透過RAPD法鑑定，顯示臺灣產胡瓜萎凋病菌株（Foc100、Foc106、Foc151及Foc183）與ATCC16416較為接近。此外利用國外所發表對Forc專一性引子對（ForcF1, ForcR2）進行鑑定，結果僅有Forc 的VCG標準菌株被增幅出277 bp DNA條帶，然臺灣產菌株、ATCC16416及Foc之VCG標準菌株皆不會被增幅出專一條帶。綜合上述測試結果，將臺灣產胡瓜萎凋病菌鑑定為Fusarium oxysporum f. sp. cucumerinum。

關鍵字

胡瓜萎凋病 ； 鑑定 ； 營養菌絲親合群 ； 專一性引子對

並列摘要

Two formae speciales (f. sp.) of Fusarium oxysporum, F. oxysporum f. sp. cucumerinum (Foc) and F. oxysporum f. sp. radicis-cucumerinum (Forc), were reported to trigger Fusarium wilt of cucumber that cause root and stem rot, respectively. However, the isolates of F. oxysporum caused Fusarium wilt of cucumber in Taiwan are not yet identified. The isolates of F. oxysporum were collected from diseased cucumber plants in Taiwan and compared with the type strain of Foc (ATCC16416), including symptoms, host range and optimum infection temperature. The results showed that all Taiwan isolates could cause root and stem rot of cucumber plants by using soil infestation inoculation method, except ATCC16416. Moreover, the Taiwan isolates Foc151 could infect cucumber, muskmelon, melon and watermelon, but isolate ATCC16416 could only infect cucumber, muskmelon and melon. Isolates Foc100 and Foc829 could infect cucumber at both 17°C and 28°C, the optimum infection temperature of other Taiwan isolates and isolate ATCC16416 were at 28°C. Twelve VCG testers of Foc and Forc were used to identify the VCG of Taiwan isolates by using the vegetative compatibility tests. The results indicated that 100M16, the nit mutant of isolate Foc100 was VCG 0180 of Foc. The specific primers of Forc (ForcF1&ForcR2) were used to detect the Taiwan isolates in this study. The results showed that only VCG testers of Forc were able to amplify a DNA fragment with 277-bp. On the contrary, the same primers were not able to amplify any PCR product from VCG testers of Foc, ATCC16416 and all of the Taiwan isolates. Based on the results of symptoms, host range, optimum infection temperature, VCG and PCR with specific primers of Forc indicated that the Fusarium wilt pathogen of cucumber obtained from Taiwan was still identified as Fusarium oxysporum f. sp. cucumerinum.

並列關鍵字

Fusarium wilt of cucumber ； identification ； vegetative compatibility group ； specific primers