濒危植物夏蜡梅光合生理生态特性  

Photosynthesis traits of the endangered plant species Sinocalycanthus chinensis

作　　者：金则新[1] 李钧敏[1] 马金娥[1] 

机构地区：[1]台州学院生态研究所,浙江临海317000

出　　处：《浙江大学学报（理学版）》2011年第6期682-688,共7页Journal of Zhejiang University（Science Edition）

基　　金：国家自然科学基金资助项目(30870392);浙江省自然科学基金资助项目(Y3080460)

摘　　要：采用遮荫的方式设置3个光照梯度:全光照(CK)、37%全光照(37%RI)和10%全光照(10%RI),于2007年7月中旬,对上述光环境中的夏蜡梅(Sinocalycanthus chinensis)幼苗的光合作用参数、叶绿素荧光参数进行测定,结果表明:3种光环境下,夏蜡梅的净光合速率日变化均为"双峰"曲线,CK和37%RI光环境下,午休现象明显;最大净光合速率的大小是37%RI>CK>10%RI;日均净光合速率的大小是37%RI>10%RI>CK.叶绿素荧光参数的日变化表明,10%RI光环境下光抑制现象不明显;37%RI光环境下在午间发生了明显的光抑制,但是光合机构可以恢复.全光照环境下发生了长期的光抑制,光合机构受到不可恢复的伤害.在夏蜡梅自然群落中,于2006年7月、10月和2007年4月下旬的晴朗天气,测定了群落冠层和林下2种光环境下夏蜡梅的净光合速率日进程,并与其主要伴生植物进行比较.7月夏蜡梅冠层的净光合速率日进程呈"双峰"曲线,有明显的"午休"现象;林下夏蜡梅则表现为"单峰"曲线;在4月和10月夏蜡梅及其伴生植物净光合速率日进程均呈"单峰"曲线.夏蜡梅3个季节的日均净光合速率的平均值比其它伴生植物低,在群落内种间竞争中将处于不利地位.Three light conditions,such as full light（CK）,37% full light（37% RI） and 10% full light（10% RI） were conducted using different shading.The photosynthesis traits and the fluorescence parameters of the endangered plant species Sinocalycanthus chinensis in three different light conditions were determined on the mid July,2007.The diurnal variations of photosynthetic rate of S.chinensis in three different light conditions are all typical curves with double peaks.The midday depression under CK and 37% RI light conditions are clear.The maximal net photosynthetic rate of S.chinensis ranked in the order： 37%RI〉CK〉10%RI.The daily net photosynthetic rate of S.chinensis ranked in the order： 37%RI〉10%RI〉CK.The diurnal variation of the inflorescence parameters indicated that the light inhibition is not clear under 10% RI light condition.The light inhibition in the middle day is clear under 37% RI light condition but the photosynthetic organs can be restored.The light inhibition can be detected all the day in full light and the photosynthetic organs can not be restored.The diurnal variations of photosynthetic rate of S.chinensis and main accompany plant species in the canopy and understory habitats in natural community were determined in July,October 2006 and April 2007.In July,the diurnal variation of photosynthetic rate of S.chinensis in the canopy is a curve with two peaks with clear midday depression while that in the understory habitat is a curve with single peak.In April and October,that of S.chinensis and the accompany plant species are all curves with single peak.The daily mean net photosynthetic rate of S.chinensis in three seasons are lower than those of the accompany plant species,which might be the main reason why S.chinensis is at a disadvantage status in the interspecific competition in the community.

关 键 词：濒危植物 夏蜡梅 光合生理参数 叶绿素荧光参数 季节动态 

分 类 号：Q948.1[生物学—植物学]