不同荫蔽度对香露兜光合特征及香气成分的影响

Effects of Shading on Photosynthesis and Aromatics of Pandan(Pandanus amaryllifolius)Plants

【目的】研究不同荫蔽度对香露兜光合特性、生长情况及香气成分的影响,为生产上林下复合种植香露兜提供理论依据。【方法】采用人工荫蔽盆栽试验的方法,设置全光照、30%荫蔽度、60%荫蔽度和90%荫蔽度等4种不同荫蔽处理,探究不同荫蔽度处理下香露兜光合参数、生长指标和香气成分对光环境的响应。【结果】荫蔽度为30%和60%时,香露兜净光合速率和气孔导度均显著高于全光照和90%遮荫处理,有利于提高香露兜的光合作用,植株叶片较多。随着荫蔽度的增加,分蘖数显著减少。4种遮荫处理下香露兜共鉴定出27种挥发性物质,2-乙酰-1-吡咯啉、叶绿醇、角鲨烯、丙醇、丙酮醇、3-甲基-2-(5H)-呋喃酮、新植二烯、棕榈酸乙酯、2,3-二氢苯并呋喃和亚油酸乙酯等10种共有香气成分含量差异显著。30%和60%荫蔽处理下香露兜叶片关键特征香气物质2-乙酰-1-吡咯啉和3-甲基-2-(5H)-呋喃酮、2,3-二氢苯并呋喃、亚油酸乙酯和叶绿醇显著高于其他处理,30%荫蔽处理角鲨烯和叶绿醇含量显著高于其他处理,60%荫蔽处理丙酮醇、2-乙酰-1-吡咯啉、3-甲基-2-(5H)-呋喃酮、新植二烯、棕榈酸乙酯和亚油酸乙酯显著高于其他处理。【结论】30%~60%荫蔽度可促进香露兜生长,提高主要香气成分含量,风味品质佳。

【Objective】Effects of shading on photosynthesis,growth,and aromatic composition of Pandan(Pandanus amaryllifolius)plants were studied for cultivation improvement.【Method】In a pot experimentation,pandan plants were grown under either full sun exposure or 30%,60%or 90%shading.The photosynthesis,growth,and aromatics of the plants were monitored.【Result】The net photosynthetic rate,stomatal conductance,and count of the leaves on plants grown under 30%and 60%shading were significantly higher than those under either full sun exposure or 90%shading.On the other hand,the tiller number decreased significantly with increasing shading.Twenty-seven volatile aromatic compounds were identified regardless the difference in treatment.There were 10 aromatics,including 2-acetyl-1-pyrrolidine phytol,squalene,1-propanol,acetol,3-methyl-2-(5H)-furanone,neophytadiene,ethyl palmitate,2,3-dihydrobenzofuran,and ethyl linoleate,commonly present,but differed significantly in relative content when the plants were under the varied shading.For instance,the contents of 2-acetyl-1-pyrroline,3-methyl-2-(5H)-furanone,2,3-dihydrobenzofuran,ethyl linoleate,and phytol were significantly higher under 30%and 60%shading,those of squalene and phytol significantly higher under 30%shading,and those of acetol,2-acetyl-1-pyrroline,3-methyl-2-(5H)-furanone,neophytadiene,ethyl palmitate,and ethyl linoleate significantly higher under 60%shading than the other treatments.【Conclusion】By artificially imposing 30%or 60%shading,pandan plants grew more vigorously generating more fragrant substances in the leaves than exposing naturally to the sun.