三個不同生態位線蟲族群其生物特性與藥劑感受性的關聯

The correlation between biological characteristics and nematicides susceptibilities of three nematodes from different habitat niche

"水稻葉芽線蟲（Aphelenchoide besseyi）廣泛分布於世界各大水稻產區，為水稻栽培重要病原，種子浸藥是一個有效的防治策略，然而長期使用同類型殺線蟲劑時，有較高的機率篩選出抗藥性蟲源。本試驗中以乙醯膽鹼脂酶抑制劑這類殺線蟲劑測試兩葉芽線蟲及一秀麗隱桿線蟲族群對藥劑之感受性，結果顯示A. besseyi strain Af對四種殺線蟲劑的感受性最低，且不同分離來源之同種線蟲或生態位不同之線蟲對於測試藥劑具有不同感受性。觀察以人工篩選對殺線蟲劑具不同耐受性之線蟲族群生活史，由較高藥劑濃度篩選之葉芽線蟲族群其生活史長度顯著變短。其中差異最大者為加保扶3,000 ppm篩選之A. besseyi strain Af族群，其生活史長度為96.8小時，而未經藥劑處理之A. besseyi strain Af族群生活史長度為151.2小時，推測葉芽線蟲對藥劑的耐受性程度與生活史長度呈負相關。分析模式線蟲秀麗隱桿線蟲之殺線蟲劑作用點乙醯膽鹼脂酶基因ace-1，發現對殺線蟲劑具有不同耐受性之秀麗隱桿線蟲族群的ace-1基因並無SNPs產生，推論其ace-1基因與殺線蟲劑之感受性無相關性。"

"Rice white tip nematode, Aphelenchoide besseyi, is an important rice pest, seeds treatment with nematicides is an effective controlling method. Using pesticides with mono function mechanism increases the possibility of selecting pesticide-resistant plant parasitic nematodes populations, however, there is only few studies on their nematicide-resistance. In the experiment, two A. besseyi populations and one Caenorhabditis elegans population were used to investigate nematicide susceptibilities, A. besseyi strain Af showed the lowest susceptibility to the tested nematicides and the results indicated that all three nematode populations had different susceptibility to these nematicides. Among the artificially selected nematicide-insusceptible A. besseyi populations, the length of life cycle time was negatively correlated with the nematicides selection dosage. The length of life cycle of A. besseyi strain Af population selected by 3,000 ppm carbofuran was 96.8 hours had significant difference from the nontreated population. Selected C. elegans populations with different nematicides as well as dosage tolerance found no SNPs occurring in their acetylcholinesterase gene ace-1 gene sequences. This result indicated that nematicide insusceptibility of C. elegans might not associated with acetylcholinesterase gene ace-1 mutation."