光照及栽培模式對四季蔥生長及揮發性成分之影響

Abstract

本研究於生長箱內栽種四季蔥地方品系‘黑葉’，以霧耕及水耕為栽培模式，並利用三種光質作為栽培光源，調查植株生長情形。另以固相微萃取法（solid-phase microextraction, SPME）及氣相層析質譜儀（gas chromatography - mass spectrometry, GC-MS）分析蔥青及根部揮發性成分。 首先為確立適宜的光強度，測得‘黑葉’於1,500±43 ppm 二氧化碳起始濃度下，測得光飽和點為382.15±27.8μmol．m-2．s-1(相當於24,993.46±1,818 lux)；二氧化碳起始濃度增至3,000±71ppm時，光飽和點大於711μmol．m-2．s-1。 霧耕及水耕栽培時，其蔥青生長速率指標(蔥青表面積)無顯著差異，但平均發根數及發根速率則以霧耕栽培較好，呈極顯著差異。 於白光、紅光及藍光下栽培，‘黑葉’ 平均葉片數生長量與表面積生長量，呈極顯著差異，以白光栽培為佳。分析揮發性成分，以新鮮葉片配合75℃加熱溫度與SPME加熱吸附7分鐘。 白光栽培下之‘黑葉’蔥青，Dipropyl disulfide、1,2-Dithiolane及Dipropyl trisulfide，高於紅光及藍光栽培者。藍光栽培者3,5-Diethyl-1,2,4-trithiolane，高於白光及紅光栽培者，紅光栽培者則所有揮發性成份皆較低。 ‘黑葉’根部所含的揮發性成分比蔥青多，而根部於藍光栽培下，5種揮發性成分(Methyl 2-propenyl disulfide、Dimethyl trisulfide、(Z)-1-(methylthio)-1-propene、(E)-1-(methylthio)-1-propene、3-Isopropyl-4-methyl-dec-1-en-4-ol)，含量顯著高於白光及紅光栽培者。白光栽培下，Dipropyl disulfide、Dipropyl trisulfide，則高於紅光與藍光栽培者，皆呈顯著差異。另外，與溫室內栽種的根部比較，三種處理的揮發性成分大多高於溫室自然光栽培者。Methyl propyl disulfide、Dipropyl disulfide、3,3-Dimethyl-piperidine、2-[(methylthio)ethynyl]-thiophene及3,5-Diethyl-1,2,4-trithiolane這5種揮發性成分含量，皆是根部大於蔥青，而1,2-Dithiolane則是蔥青大於根部。

The purpose of this study is to investigate the growing of a local strain-Black leaf, a variety of green onion called Shy-Zih, They were planted in the growth chambers for fogoponic and hydroponic culture systems. Three kinds of light qualities are used as artificial light source. Additionally, the solid-phase microextraction (SPME) and gas chromatography - mass spectrometry (GC-MS) were used to analyze the volatile components from the leaves and roots. First is to establish the proper light intensity, the measured light saturation point of the “Black leaf” is 382.15 ± 27.8μmol．m-2．s-1 (equivalent to 24,993.46 ± 1,818 lux) if the initial concentration of carbon dioxide was at 1,500±43 ppm; when the initial concentration of carbon dioxide increased at 3,000±71pp, the light saturation point is greater than 711μmol．m-2．s-1. No significant difference in the green-leaf growth rate (green-leaf surface area) by fogoponic and hydroponic culture systems. But the average of rooting number and growth rate with fogoponic cultivation is better. Under the white, red and blue light, the average growth number of leaf and surface area of “Black leaf” it makes significant difference among them and it grows best under the white light. The analyzing condition of the volatile components of fresh leaves is to heat temperature up to 75 ℃ and SPME heating adsorption for 7 minutes. The Dipropyl disulfide、1,2-Dithiolane and Dipropyl trisulfide of green-leaf of 'Black Leaf” contents is higher than it grown under red and blue light. The 3,5-Diethyl-1,2,4-trithiolane contents is higher than it grown under other two kinds light and the volatile compounds are the lowest among all. The roots of the “Black-leaf” content more volatile compounds than the green-leaf. If the roots are grown under the blue light, the 5 kinds of volatile compounds(Methyl 2-propenyl disulfide、Dimethyl trisulfide,(Z)-1-(methylthio)-1-propene、(E)-1-(methylthio)-1-propene、3-Isopropyl-4-methyl-dec-1-en-4-ol) content are higher than it grown under red and blue light and the difference is very significant. Besides, compare with the roots grown in greenhouse, the 3 kinds of volatile compounds are higher than it was grown under the natural light. The 5 kinds of volatile compounds of roots, Methyl propyl disulfide、Dipropyl disulfide、3,3-Dimethyl-piperidine、2-[(methylthio)ethynyl]-thiophene and 3,5-Diethyl-1,2,4-trithiolane, are higher than the green-leaf but the 1,2-Dithiolane is opposite.