首页 | 本学科首页   官方微博 | 高级检索  
   检索      

热带雨林不同生态习性树种幼苗光合作用和抗氧化酶对生长光环境的反应
引用本文:郭晓荣,曹坤芳,许再富.热带雨林不同生态习性树种幼苗光合作用和抗氧化酶对生长光环境的反应[J].应用生态学报,2004,15(3):377-381.
作者姓名:郭晓荣  曹坤芳  许再富
作者单位:1. 中国科学院西双版纳热带植物园,勐腊,666303;中国科学院昆明植物研究所,昆明,650204
2. 中国科学院西双版纳热带植物园,勐腊,666303
基金项目:中国科学院百人计划资助项目
摘    要:于雨季研究了西双版纳热带雨林后期演替树种思茅木姜子(Litsea pierrei var.szemaois)、五桠果叶木姜子(L.alilleniifolia)和先锋树种毛果桐(Mallotus barbatus)幼苗的光合、荧光特征和抗氧化酶等对3种光水平(50%、25%和8%)的适应特性。结果表明,毛果桐的最大光合速率(Pmx)随光水平升高呈增加趋势,而两种木姜子则在50%光水平下Pmax最小,Fv/Fm的日变化表明,3个种在25%和50%光水平下发生可逆光抑制,两种木姜子较重,50%光水平下,五桠果叶木姜子受到长期光抑制.思茅木姜子和毛果桐的丙二醛(MDA)和H2O2含量,以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性随光水平升高而增加,表明光水平升高,致使植物受光胁迫的影响加剧,增强抗氧化酶系统则减轻了其伤害,两种木姜子的濒危现状可能和它们对强光生境的适应性较差有一定关系。

关 键 词:热带雨林  生态习性  树种  幼苗  光合作用  抗氧化酶  光抑制  光适应  保护酶系统  可塑性
文章编号:1001-9332(2004)03-0377-05
修稿时间:2002年10月5日

Response of photosynthesis and antioxygenic enzymes in seedlings of three tropical forest tree species to different light environments
GUO Xiaorong ,CAO Kunfang ,XU Zaifu.Response of photosynthesis and antioxygenic enzymes in seedlings of three tropical forest tree species to different light environments[J].Chinese Journal of Applied Ecology,2004,15(3):377-381.
Authors:GUO Xiaorong    CAO Kunfang  XU Zaifu
Institution:Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China. guoxr75@hotmail.com
Abstract:This paper studied the response of photosynthesis, chlorophyll a fluorescence and 3 antioxygenic enzyme activities in the seedlings of a pioneer species (Mallotus barbatus) and two endangered sub-canopy tree species (Litsea pierrei var. szemaois and L. dilleniifolia) in Xishuangbanna tropical rain forest to different light environments. Three light regimes (50%, 25% and 8% full sunlight) were designed for the seedlings. The largest values of maximum photosynthetic rates (Pmax) of L. pierrei var. szemaois and L. dilleniifolia were documented at 25% and 8% sunlight, respectively, which showed that the two sub-canopy species had poor ability in photosynthetic acclimation to high light. In contrast, the Pmax of M. barbatus increased with light level. During a day, the maximum photochemical efficiency (Fv/Fm) of the photosystem II in all the three species grown under three light levels showed minimum values at noon, and the lowest Fv/Fm values were shown in seedlings at 50% sunlight. Under 50% sunlight, the Fv/Fm values at dawn were lower in L. dilleniifolia than in the same species under other two light levels, indicating that sustained photoinhibition occurred in this case. The contents of malondialdehyde (MDA), H2O2, and activities of ascorbate peroxidase (APX), superoxid dismutase (SOD), catalase (CAT) of both L. pierrei var. szemaois and M. barbatus increased with stronger irradiance, which revealed that these two species were able to alleviate photodamage under high light stress by increasing their antioxigenic activities. But, high content of MDA revealed that L. dilleniifolia was probably suffered from membrane damage. In conclusion, our data revealed that the pioneer species M. barbatus had a high capacity to acclimate to different light environments, particularly high light, while the two subcanopy Litsea species had poor ability in acclimation to high light. Based on the findings of the present study, we suggest that the small populations and endangered status of both L. pierrei var. szemaois and L. dilleniifolia in natural environment could be partially due to their poor flexibility in response to changed light environment resulted from habitat fragmentation.
Keywords:Tropical rain forest  Endangered species  Photoinhibition  Photosynthetic acclimation  Antioxygenic enzymes  Flexibility  
本文献已被 CNKI 维普 万方数据 等数据库收录!
点击此处可从《应用生态学报》浏览原始摘要信息
点击此处可从《应用生态学报》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号