文心兰浅绿条纹突变体的生理生化及叶绿素荧光特性研究  

Physiological,Biochemical and Chlorophyll Fluorescence Characters of Light Green Stripe Mutant in Oncidium

作　　者：田韦韦 王彩霞[1] 田敏[1] 欧阳彤[1] 张莹[1] 

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江省林木育种技术研究重点实验室,杭州311400

出　　处：《西北植物学报》2015年第10期2012-2017,共6页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31301801);中央级公益性科研院所基本科研业务费(CAFYBB2014QB012)

摘　　要：以文心兰浅绿条纹突变体为材料,分析叶片光合色素含量和组成、叶绿素合成前体物质含量以及叶绿素荧光参数的变化,观察突变体叶绿体超微结构的改变,以探寻其叶色变异的生理基础。结果表明:(1)突变体叶绿素a(Chl a)、叶绿素b(Chl b)、类胡萝卜素(Car)和总叶绿素(Chl)含量分别比叶色正常植株显著降低了37.1%、34.0%、30.8%和36.3%。(2)突变体叶绿素生物合成受阻于胆色素原(PBG)到尿卟啉原Ⅲ(UrogenⅢ)的反应步骤。(3)突变体叶绿体发育存在明显的缺陷,基粒数目及基粒片层的垛叠层数明显减少,嗜锇颗粒及囊泡较多。(4)突变体初始荧光(Fo)比正常植株高39%,最大荧光(Fm)、最大光化学效率(Fv/Fm)、PSⅡ有效光化学效率(Fv′/Fm′)和PSⅡ实际光化学效率(ΦPSⅡ)均显著低于正常植株,但光化学淬灭系数(qP)和非光化学淬灭系数(NPQ)与正常植株无显著差异。研究结果说明,文心兰叶绿素生物合成受阻和叶绿体结构发育不良,导致叶绿素的含量下降,致使突变体叶片呈现浅绿条纹,光能利用率降低。In order to understand the physiological basis of a light green stripe mutant of Oncidium ‘Milliongolds＇,we investigated the changes of the photosynthetic pigments and chlorophyll synthesis precursors contents,ultra-structure of chloroplasts and chlorophyll fluorescence parameters.The results showed that：（1）the contents of chlorophyll a（Chl a）,chlorophyll b（Chl b）,carotenoids（Car）and total chlorophyll（Chl）in mutant leaves revealed a remarkably decreased tendency,to decreased by 37.1%,34.0%,30.8% and 36.3%respectively（P0.05）.（2）The biosynthesis of chlorophyll in mutant was blocked at the reaction from prophobilinogen（PBG）to uroporphyrinogen（UrogenⅢ）.（3）In mutant leaves,the number of chloroplast reduced and there were some abnormal chloroplasts with less grana lamellas,as well as more osmioplilic granules and vesicae.（4）The minimal fluorescence（Fo）of mutant was 39% higher than that of normal plant.Compared with normal plant,the maximal fluorescence（Fm）,maximum quantum yield of PSⅡ（Fv/Fm）,photochemical efficiency of PSⅡin the light（Fv′/Fm′）and actual photochemical efficiency of PSⅡ（ΦPSⅡ）reduced significantlyin mutant,while the photochemical quenching（qP）and non photochemical quenching coefficient（NPQ）of mutant were not significantly different from that of normalplant.It was concluded that the blockage of chlorophyll biosynthesis and aberrant chloroplast lead to the decrease of chlorophyll contents,light green stripe of leaves and light-harvesting capacity in mutant.

关 键 词：文心兰 浅绿条纹突变体 光合色素 叶绿素合成前体物质 超微结构 叶绿素荧光 

分 类 号：Q945.3[生物学—植物学]