不同温度下新铁炮百合幼苗的光合特性及其保护机制  

Photosynthetic Characteristics and Photoprotective Mechanisms under Vari-ous Temperatures in Lilium ~formolongo Seedlings

作　　者：罗丽兰[1] 石雷[1] 姜闯道[1] 张金政[1] 

机构地区：[1]中国科学院植物研究所

出　　处：《园艺学报》2008年第1期131-136,共6页Acta Horticulturae Sinica

基　　金：中国科学院重要方向性项目(KSCX2-YW-N-52);国家科技部平台项目(2005EA700043；2005DKA21006)

摘　　要：以新铁炮百合的两个主栽品种‘雷山一号’和‘Savaka’为材料,对其幼苗在不同温度下(25℃、32℃、38℃和44℃)的光合特性及光保护机制进行了研究。结果表明,在低于38℃时净光合速率(Pn)下降幅度较小,高于38℃时显著下降。随着处理温度的提高,气孔导度(Gs)呈下降的趋势,胞间二氧化碳浓度(Ci)上升,气孔限制值(Ls)下降。不同处理温度下,两品种叶片最小荧光(Fo)无明显变化,最大荧光(Fm)和光系统Ⅱ(PSⅡ)最大光化学效率(Fv/Fm)下降程度较小。光下PSⅡ实际光化学效率(φPSⅡ)呈持续下降趋势,而非光化学猝灭系数(NPQ)则随处理温度的提高而迅速增加。超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)和过氧化物酶(POD)活性随处理温度升高而提高。本研究表明‘雷山一号’和‘Sayaka’幼苗能够耐受32～38℃的高温;在较高的处理温度下,叶片可以通过提高非光化猝灭和抗氧化酶活性两种机制来保护光合机构免受伤害。Gas exchange, chlorophyll fluorescence and activities of anti-oxidant enzymes were investigated to study the responses of photosynthetic characteristics and photoprotective mechanisms to various temperatures （25 ℃, 32 ℃, 38 ℃ and 44 ℃ ） in ‘ Leishan 1 ＇ and ‘ Sayaka＇ of Lilium xformolongo seedlings. The results showed that the temperatures from 25 ℃ to 38 ℃ led to only slight decrease in photosynthetic rate （ Pn）, but temperature at 44 ℃induced a significant reduction in the values of Pn. Along with the decrease in photosynthetic capacity, stomatal conductance （Gs） decreased considerably ; during this process, the stomatal limitation value （Ls） decreased gradually and clearly. The measurement of chlorophyll fluorescence showed that the initial fluorescence yield （Fo） was not effected by the raising temperatures, while the maximum fluorescence yield （Fro） and the maximal quantum yield of photosystem Ⅱ photochemistry （Fv/Fm） went down slightly with temperature increasing in seedlings of the two lily varieties. The actual efficiency of PS Ⅱ （ФPS Ⅱ ） reduced distinctly along with the increase of temperature, while non-photochemical quenching （NPQ） strikingly increased. Moreover, the activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT） and peroxidases （POD） were enhanced with the temperature increasing. According to the experimental data show that Lilium xformolongo is able to tolerate mild high temperatures; Non-photochemical quenching and the anti-oxidant enzymes are the main mechanisms in seedlings of the two lily varie-ties, which can effectively protect its photosynthetic apparatus against high temperatures.

关 键 词：百合 新铁炮百合 耐热性 气体交换 叶绿素荧光 抗氧化酶 

分 类 号：S682.2[农业科学—观赏园艺]