Daphnephila 屬癭蚋蟲癭之生態生理特性研究

Abstract

造癭昆蟲會改變植物組織的生長與分化，產生的蟲癭可提供昆蟲營養及遮蔽，而造癭昆蟲也會造成植物組織內化學組成、色素蛋白複合體、光合作用效能等多方面的改變。本研究使用Daphnephila 屬之兩種癭蚋蟲癭，利用化學分析、氣體交換、葉綠素螢光、掃描式電子顯微鏡、共軛焦雷射掃描顯微鏡及反射光譜等，研究葉片癭蚋蟲癭和寄主植物的生態生理特性。結果顯示造癭昆蟲會改變葉片組織葉綠素的生合成及崩解途徑，由Chlide→ Phe→ Pchlide 改變為Chl→ Chlide→ Pchlide；在營養假說的基礎上，研究結果顯示蟲癭在寄主植物上可扮演基儲的角色；而反射光譜研究結果顯示，反射光譜指數與葉綠素螢光參數呈現正相關，反射光譜技術具有利用於蟲癭生態生理研究的潛力；由蟲癭及葉片抗氧化功能的分析結果顯示，蟲癭會提高抗氧化的能力來清除組織內增加的自由基。

Many insect groups induce plant galls – structures composed of plant tissue within which the insect feeds, which are distinguished from other insect-generated shelters by the fact that they involve active differentiation and growth of plant tissues. Multiple changes in response to gall inducers have been found in host plant tissues. In this study, two types of galls induced by two Daphnephila midge species were focused. Chemical analysis, gas exchange, chlorophyll fluorescence, scanning electron microscopy, confocal laser-scanning microscopy and reflectance spectra were used to investigate the ecophysiological characteristics of leaf-derived cecidomyiid galls and their host leaves. The results showed that the insect induced galls derived from infected leaf altered the biosynthetic and degradative pathways of chlorophyll. Based on assumptions of source-sink hypothesis, it suggests that leaf-derived cecidomyiid galls play the role as novel sink in leaves. The data of spectral reflectance revealed the potential of utilizing it as a tool for studying the ecophysiology of galls. The results indicated that galls had abilities and functions to scavenge free radicals effectively for balancing the increase of free radicals in their bodies.