不同生境吉首蒲儿根叶片形态和叶绿素荧光特征的比较

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 不同生境吉首蒲儿根叶片形态和叶绿素荧光特征的比较 DOI: 10.5846/stxb201210291501 作者: 作者单位: 吉首大学 植物资源保护与利用湖南省高校重点实验室,吉首大学 植物资源保护与利用湖南省高校重点实验室,吉首大学 植物资源保护与利用湖南省高校重点实验室,吉首大学 植物资源保护与利用湖南省高校重点实验室,吉首大学 植物资源保护与利用湖南省高校重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 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） Leaf morphology and PSⅡchlorophyll fluorescence parameters in leaves of Sinosenecio jishouensis in Different Habitats Author: Affiliation: Key laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou,Key laboratory of Plant Resources Conservation and Utilization, College of Hunan Province, Jishou,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 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ETRmax、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ETRmax、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。 Abstract:Sinosenecio jishouensis 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 PSⅡchlorophyll fluorescence parameters in leaves of S. jishouensis 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 jishouensis 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 were measured at various light intensities (8, 16, 32, 90, 165, 245, 325, 430, 580, 770, 1100, 1400, 1700, 2100 μmol · m-2 · s-1) by PAM-2500 chlorophyll fluorimeter. We observed that the maximal PSⅡquantum yield (Fv/Fm), latent PSⅡ 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 (ETRmax), minimum saturating irradiance(Ik), the coefficient of photochemical quenching (qP) and the effective PSⅡ quantum yield (Y(Ⅱ)) of S. jishouensis in sun habitat were higher than other 4 habitats, above 4 parameters in valley understory habitat were significantly lower than other 4 habitats, at the same time, those values showed no significant difference among valley falls habitat, valley sidehill habitat and shade habitat.It thus indicated that S. jishouensis had tolerance to greater light intensity and moderate air humidity realized by reduced leaf area, specific leaf area, and increased stomata density, SPAD value, improved NPQ and Y(Ⅱ). while low light intensity and high relative humidity was not an important ecological factor in limiting development of S. jishouensis, providing a theoretical foundation for ex situ conservation of S. jishouensis. However, the major environment factors limiting distribution of S. jishouensis and the main causes for the endangered status of S.jishouensis still needed further investigation. 参考文献 相似文献 引证文献