生長抑制劑PP333對小本山葡萄組培苗生長發育之影響

Abstract

本論文以小本山葡萄( Vitis thunbergii Sieb. & Zucc. var. taiwaniana Lu. )單節帶芽莖段為試驗材料，探討PP333對小本山葡萄組培苗及不定根之生長發育的影響，並測試GA3與IAA是否有逆轉PP333影響的作用；論文中也觀察PP333與GA3對甘藷、菸草與甜菊生長發育之影響。試驗結果顯示四種受試植物都因PP333的處理而有地上部變矮、節間縮短、葉片變小、葉色加深的現象。PP333使小本山葡萄有明顯根長變短、根徑變大的形態變化，且表現側根易脫離主根而斷裂的情形；甘藷與菸草根系發育受抑制，但無根徑加粗之變化，且隨著培養時間的拉長，抑制效果漸趨不明顯，而甜菊根系發育嚴重受抑制且根變粗，甚至導致死亡。外加GA3無法回復PP333抑制小本山葡萄地上部生長的效果，但可部分緩解根部膨大之異常現象；而外加IAA則無解除PP333抑制的任何效果。GA3對甘藷、菸草、甜菊的根受PP333抑制的現象有回復的效果，但無法使三種受試植物的地上部回復正常生長。切片觀察因PP333處理而膨大的小本山葡萄根部組織，發現中柱直徑增大，皮層的細胞層數與細胞直徑也大於對照組，其中皮層細胞層數增加的程度最顯著。外加GA3至含有PP333的處理組，會使植株的根端直徑、皮層細胞層數與細胞直徑均略為回復，但無法改善PP333造成側根易脫離主根的現象。綜合之，1.0 mg/L PP333嚴重抑制小本山葡萄培植體的生長發育，此作用應可延長組培苗繼代移植的時間間隔，節省以瓶苗保存物種的勞力。

To study the effects of paclobutrazol (PP333) on the growth of Vitis thunbergii Sieb. & Zucc. var. taiwaniana Lu., an in vitro culture system using single-node segment was established in this study. In addition to Vitis thunbergii, sweet potato, tobacco and stevia were also used to examine the effects of PP333. Plantlets derived from single-node cuttings grown in PP333-containing media showed apparent alteration of phenotype, such as stunted shoot, shortened internodes, small leaves with dark color. Besides, PP333 also caused the reduction of root length and increase in root thickness. Unlike the other three species tested, the branching roots of Vitis thunbergii were brittle and easily detached from major roots. Gibberellic acid ( GA3 ) and indole-3-acetic acid ( IAA ) were tested for the resumption effect against the action of PP333. Exogenous GA3 could partially alleviate the root thickening, but could not abolish the inhibitory effects of PP333 on shoot growth in V. thunbergii, while IAA had no effect. Root growth of PP333-treated sweet potato and tobacco could be completely restored by application of GA3, and shoot growth did not. According to the results of anatomical analysis, root thickening caused by PP333 treatment could be attributed to increases in stele diameter, cortical cell layers and cell size. GA3 application could partially reverse the effect of PP333 on cortical cell layers and cell size, but could not alter the brittle property of branch roots. Our results also showed that the strong inhibition of 1 mg/L PP333 on in vitro growth of V. thunbergii var. taiwaniana was gradually alleviated during the period of prolonged culture. And it is suggested that including PP333 in medium can be applied to in vitro germplasm conservation of V. thunbergii var. taiwaniana in order to saving labor work of subculture.