巴克素促進轉基因赤桉花芽分化

本研究施用巴克素於6個月生基因轉殖赤桉嫁接苗，檢測巴克素處理後提早開花之效果，對苗木生長之影響以及內生激勃素、離層酸與吲乙酸含量之變化與巴克素於葉部之殘留分析。巴克素100%使6個月生基因轉殖赤桉提早開花，莖部注射與土壤施灌的效果延續兩年，巴克素處理後造成節間縮短，且葉部顏色變淡，苗木基部產生氣根現象。種子沒有受到藥劑影響可以正常發育與發芽。巴克素阻斷激勃素早期合成，試驗結果顯示赤桉花芽分化期間巴克素無法抑制激勃素GA1，GA3，GA4，GA8，GA20，GA24以及GA53等形式合成。但巴克素卻使內生離層酸與吲乙酸含量下降約1/3。利用熱裂解儀與氣相層析質譜儀分析巴克素殘留，在花芽分化時檢測三年含量每克乾重分別為34.7，0.31，0μg。

關鍵字

巴克素；赤桉；開花誘導；激勃素；離層酸

並列摘要

This paper reports a series of experiments in which paclobutrazol was applied to 6-mo-old transgenic Eucalyptus camadulensis grafts to examine its relative effects on precocious flowering, growth, and levels of gibberellin (GA), abscisic acid (ABA), indoleacetic acid (IAA), and paclobutrazol residues in the shoot apex. Paclobutrazol was effective in promoting precocious flowering in E. camadulensis. Responses to a trunk injection and soil drenching persisted for up to 2 yr, but growth responses were not expressed for another year. Paclobutrazol reduced internode length, and leaves appear less green. Paclobutrazol induced aerial roots at the basal portion of the grafts. Assessment of seed yield per capsule and subsequent germination tests showed no deleterious effects on seed development or quality. Paclobutrazol is known to block gibberellin production early in the biosynthesis pathway, but it cannot inhibit endogenous gibberellin biosynthesis, including GA1, GA3, GA4, GA8, GA20, GA24, and GA53 during flower bud initiation. Paclobutrazol treatment reduced endogenous ABA and IAA levels by about 1/3. During flower bud initiation, paclobutrazol residues in the shoot apex as determined by pyrolysis-gas chromatography-mass spectrometry were 34.7, 0.31, and 0μg•g^(-1) dry weight in the 1(superscript st) to 3(superscript rd) yr after treatment, respectively.

並列關鍵字

paclobutrazol ； Eucalyptus camadulensis ； flower induction ； gibberellin ； ABA

國際替代計量

巴克素促進轉基因赤桉花芽分化

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