氮素濃度及型態對三種香蜂草Melissa officinalis、M. officinalis ‘Quedlingburger’與M. officinalis Citronella’香氣成分與生長的影響

Abstract

本試驗探討氮素濃度及型態對三種香蜂草（Melissa officinalis、M. officinalis ‘Quedlingburger’與M. officinalis ‘Citronella’）生長、精油產量、精油主要成分以及葉片揮發性香氣成分的影響，以建立生產上合理的氮肥施用範圍。 Melissa officinalis、M. officinalis ‘Quedlingburger’ M. officinalis ‘Citronella’分別以七種氮素濃度之溶液（0 mM、4 mM、8 mM、12 mM、16 mM、20 mM、24 mM）連續施用八週，每週兩次，每次300 mL，其枝條數及葉片數皆隨氮肥濃度增加而增加。以枝條數而言，Melissa officinalis以20 mM處理最多，M. officinalis ‘Quedlingburger’ 及M. officinalis ‘Citronella’則以24 mM處理最多。以葉片數而言，Melissa officinalis以16 mM處理最多，其餘兩種則以24 mM處理最多。 以地上部鮮重而言，三種香蜂草皆以24 mM處理最多。地上部乾重在M. officinalis以20 mM處理最重，M. officinalis ‘Quedlingburger’及M. officinalis ‘Citronella’則以24 mM處理最重。每單位鮮重精油產量在M. officinalis及M. officinalis ‘Citronella’以16 mM處理最多，M. officinalis ‘Quedlingburger’則以8 mM處理最多。以每單位乾重精油產量而言，Melissa officinalis及M. officinalis ‘Quedlingburger’以24 mM處理最多，M. officinalis ‘Citronella’則以16 mM處理最多。 利用SPME萃取揮發性香氣後以GC-MS進行香氣成分分析，結果顯示三種香蜂草的主要成分為geranial及neral，兩者合計約佔89.53-98.48％，其餘主要香氣成分為nerol、geraniol、geranyl formate、geranyl acetate、以及β-caryophyllene。 連續四週分別以20 mM的硝酸態氮（NO3-－N）、銨態氮（NH4＋－N）以及尿素氮營養液（Urea－N）進行根部澆灌，結果顯示尿素氮可使M. officinalis有最多的葉片數及枝條數，而銨態氮則可使M. officinalis ‘Quedlingburger’及M. officinalis ‘Citronella’ 有最多的葉片數。葉片揮發性香氣主要成分neral及geranial之相對含量（AI），M. officinalis ‘Citronella’明顯少於M. officinalis及M. officinalis ‘Quedlingburger’。整體而言，三種香蜂草的揮發性香氣總量隨處理時間而下降，於處理兩週後開始上升。 在銨態氮與硝酸態氮處理組中，M. officinalis的SPAD計計讀值與葉綠素含量間呈顯著相關，相關係數分別為R2=0.94，R2=0.97，而對M. officinalis ‘Quedlingburger’及M. officinalis ‘Citronella’而言，硝酸態氮處理組的SPAD計計讀值與葉綠素含量間的相關性最高，相關係數分別為R2=0.91，R2=0.96，而三種香蜂草尿素處理組SPAD計計讀值與葉綠素含量的相關性皆未達顯著水準。

This research aims at the effect of nitrogen concentration and form to Melissa officinalis,M. officinalis 'Quedlingburger' and M. officinalis 'Citronella' on growth and volatile compound of leaf and essential oil, to establish a reasonable nitrogen application scope in production. M. officinalis, M. officinalis 'Quedlingburger' and M. officinalis 'Citronella' were feed respectively by 7 level of nitrogen concentration solution (0 mM, 4 mM, 8 mM, 12 mM, 16 mM, 20 mM, 24 mM) continuously eight weeks, twice a week , each time 300 mL, the number of shoot and leaf all increased along with the nitrogen concentration increasing. The most number of shoots occurred by 20 mM treatment for M. officinalis, and by 24 mM treatment for M. officinalis 'Quedlingburger' and M. officinalis 'Citronella'. The most number of leaf occurred by 16 mM treatment for M. officinalis and by 24 mM treatment for M. officinalis 'Quedlingburger' and M. officinalis 'Citronella'. The most dry weight of aboveground part occurred by 20 mM treatment for M. officinalis and by 24 mM treatment for M. officinalis 'Quedlingburger' and M. officinalis 'Citronella'. The most essential oil per unit fresh weight occurred by 16 mM treatment for M. officinalis and M. officinalis 'Citronella', and by 8 mM treatment for M. officinalis 'Quedlingburger'. The most essential oil per unit dry weight occurred by 24 mM treatment for M. officinalis and M. officinalis 'Quedlingburger' , and by 16 mM treatment for M. officinalis 'Citronella'. The composition of essential oil analysed by SPME and GC-MS showed that the main compounds of M. officinalis, M. officinalis 'Quedlingburger' and M. officinalis 'Citronella' were geranial and neral, approximately composed 89.53-98.48%, other main compounds were nerol, geraniol, geranyl formate, geranyl acetate and β-caryophyllene. M. officinalis, M. officinalis 'Quedlingburge' and M. officinalis 'Citronella' were feed 4 weeks respectively by 20mM nitrate form nitrogen solution (NO3- - N) and ammonium form nitrogen solution (NH4 + - N) and urea nitrogen solution (Urea - N), the most number of leaf and shoot occurred by urea form nitrogen treatment for M. officinalis and the most number of leaf occurred by ammonium form nitrogen solution treatment for M. officinalis 'Quedlingburger' and M. officinalis 'Citronella' The analysis of volatile compounds of leaf from M. officinalis, M. officinalis 'Quedlingburger' and M. officinalis 'Citronella' after different nitrogen form solution treatment by SPME and GC-MS showed that their main compounds were neral and geranial, and the total AI（Area index）value dropped along with treatment time, and started to rise 2 weeks later. In correlation analysis between SPAD reading and the ethanol extractable chlorophyll, the correlation coefficient respectively was R2=0.94, R2=0.97 for M. officinalis by the ammonium form nitrogen solution treatment and by the nitrate form nitrogen solution treatment, and the correlation coefficient respectively was R2=0.91, R2 =0.96 for M. officinalis ‘Quedlingburger' and M. officinalis 'Citronella' by nitrate form nitrogen solution treatment. While the correlation didn’t reach significant level for three kind of M. officinalis by urea nitrogen solution treatment