研究彙報第八十九期 ， Page 1- 9，出版時間：2005- 12， 詳細內容

萵苣萎凋病菌fmk1基因突變菌株之篩選

作者： 洪爭坊

摘　　要

 　　 利用紫外燈照射法誘變萵苣萎凋病菌 Fusarium oxysporum f.sp. lactucae LFO 32-14 菌株，並以培養皿接種法測試誘變菌株在接種後第六天對萵苣幼苗的纏據率，初步獲得 F. oxysporum f.sp. lactucae UV02-0090 、 UV02-0110 及 UV02-0130 三菌株纏據萵苣幼苗根部的百分率明顯下降，惟它們的形態與野生型菌株並無顯著差異。利用 Di Pietro (2001) 報導的F. oxysporum 致病性相關 fmk1 基因的 oliFmk1 與 oliFmk2 引子對，針對萵苣萎凋病菌野生型菌株與誘變菌株進行聚合酶連鎖反應，結果發現野生型菌株與突變菌株均可被增幅出大小約 1.2 kb 的基因片段。其中， UV02-0090 菌株的fmk1 部份基因片段序列與其他菌株的序列差異較大，而經由轉譯後發現其 Fmk1 的胺基酸序列在第 167 至第 237 個胺基酸區間具有較大的變異。

關鍵字： 萵苣，萎凋病，病原性基因 。

Screening for fmk1 Gene Mutants from Fusarium oxysporum f.sp. lactucae

Cheng-Fang Hong

ABSTRACT

　　 Lettuce Fusarium wilt caused by Fusarium oxysporum f.sp. lactucae was a serious disease in summer production of lettuce. In order to characterize the pathogenic genes of the pathogen, ultra-violet light was applied for inducing mutation of the pathogen. Di Pietro et al.(2001) suggested that the fmk1 gene was related with the pathogenensis of Fusarium oxysporum. Three ultra-violet irradiation induced mutant isolates, UV02-0090, UV02-0110, and UV02-0130, with lower infection rate were obtained by inoculation test. Two primers, oliFmk1 and oliFmk2, were used to amplify fmk1 gene fragment from wild type and the three mutant isolaes of Fusarium oxysporum f.sp. lactucae. The results showed that a 1.2 kb gene fragment was amplified from both wild-type and mutant isolates. Sequences alignment of partial fmk1 gene showed many differences between UVO2-0090 and the other isolates, and the amino acid sequences alignment showed a highly mutated region from the 167 to the 237 residues of UV02-0090 Fmk1 sequence.

Key words: lettuce, Fusarium wilt, pathogenic gene.