不同生境吉首蒲儿根叶片形态和叶绿素荧光特征的比较  

Leaf morphology and PSⅡchlorophyll fluorescence parameters in leaves of Sinosenecio jishouensis in Different Habitats

作　　者：向芬[1] 周强[1] 田向荣[1] 陈功锡[1] 肖艳[1] 

机构地区：[1]吉首大学植物资源保护与利用湖南省高校重点实验室,吉首416000

出　　处：《生态学报》2014年第2期337-344,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(31260056);湖南省教育厅重点资助项目(09A073);湖南省重点学科建设资助项目(JSU0713Z21);湖南省教育厅高等学校科学研究资助项目(12C0300);植物资源保护与利用湖南省高校重点实验室开放资助项目(13jdzb098)

摘　　要：吉首蒲儿根为近年发现的自然分布狭窄的珍稀植物,为了揭示其对不同生境的适应能力及机制,选择野外自然分布的3种河谷生境和人工引种的2种河谷外生境中的吉首蒲儿根为研究对象,比较其叶片形态和叶绿素荧光特征。研究发现,3种河谷生境吉首蒲儿根的叶面积、比叶面积要高于2种河谷外生境,而气孔密度、SPAD值则低于2种河谷外生境。5种生境吉首蒲儿根的Fv/Fm、Fv/Fo、Y(NPQ)没有显著差别,但谷外阳生生境下的吉首蒲儿根ETR max、Ik、qP和Y(Ⅱ)均高于其它各生境,而河谷林下生境吉首蒲儿根的ETR max、Ik、qP和Y(Ⅱ)均显著低于其它各生境,河谷瀑布生境、河谷山坡生境、谷外阴生生境吉首蒲儿根的以上4参数则无显著差别。结果表明:吉首蒲儿根能够通过减小叶面积、比叶面积,增加气孔密度、SPAD值来调整叶片结构,积极调控调节性能量耗散NPQ,提高PSⅡ实际光量子效率Y(Ⅱ)来适应较高的光照和中等空气相对湿度环境。Sinosenecio fishouensis D.G. Zhang, Y. Liu ＆ Q.E.Yang is a new Asteraceous species, and is considered as a critically endangered species because its population is extremely small. Currently, only several natural populations of S. jishouensis are discovered in Dehang canyon which is at northwestern Hunan, China, and is characteristic of low light intensity and high relative humidity. An interesting question is thus whether or not the distinct habitat conditions are related to its growth and distribution. Generally, its natural habitats consist of valley falls habitat, valley sidehill habitat and valley understory habitat. In order to reveal the adaptive ability to different environments and the underlying mechanisms, S. jishouensis were transplanted from valley to sun habitat and shade habitat. Since the light intensity and the relative humidity are different among 5 habitats, especially, there are higher light intensity and lower relative humidity in 2 artificial distribution habitats than in 3 natural distribution habitats, the leaf morphology and PS I1 chlorophyll fluorescence parameters in leaves of S. fishouensis within above 5 habitats were investigated. The results showed that： as compared with 3 natural distribution habitats, the leaf area, specific leaf area of Sinosenecio fishouensis were smaller and their stomata density, SPAD value were higher in 2 artificial distribution habitats, especially in sun habitat. On the other hand, the rapid light-response curves of chlorophyll fluorescence parameters weremeasured at various light intensities （8, 16, 32, 90, 165, 245, 325, 430, 580, 770, 1100, 1400, 1700, 2100 p^mol＂ m-2＂s-1） by PAM-2500 chlorophyll fluorimeter. We observed that the maximal PS ]I quantum yield （Fv/Fm） , latent PS ]l quantum yield （ Fv/Fo ）, the quantum yield of regulated energy dissipation （ Y （ NPQ ） ） had no significant difference between 5 habitats. However, the maximal electron transport rate （ETRm,x）, minimum saturating irradiance （Ik）, the coeffici

关 键 词：叶片形态 叶绿素荧光 河谷生境 吉首蒲儿根 

分 类 号：Q945[生物学—植物学]