| 大花紫薇幼苗光合、荧光特性对光照的响应 |
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| 引用本文： | 周袁慧子,王艺锦,潘会彪,王凌晖,滕维超,周维.大花紫薇幼苗光合、荧光特性对光照的响应[J].湖北农业科学,2016(24). |
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| 作者姓名： | 周袁慧子 王艺锦 潘会彪 王凌晖 滕维超 周维 |
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| 作者单位： | 1. 广西大学林学院,南宁,530004;2. 广西国有大桂山林场,广西 贺州,542800 |
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| 基金项目： | 广西壮族自治区林业科技项目(桂林科字[2012]第25号) |
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| 摘 要： | 采用遮光处理模拟不同的生境光强(全光照100%NS、1层遮光42.1%NS、2层遮光14.3%NS和3层遮光3.6%NS),测定不同光照水平下大花紫薇Lagerstroemia speciosa(L.)Pers.]叶片的光合色素含量、光响应曲线、叶绿素荧光参数等光合生理指标。结果表明,叶绿素a、叶绿素b和总叶绿素含量随着光照水平降低呈先上升后下降的变化趋势,在14.3%NS光照条件下达最大值,100%NS条件下叶绿素a/b值最大,是14.3%NS条件下的1.7倍;3个遮光处理的大花紫薇幼苗光响应曲线随光合有效辐射的增加,净光合速率先快速增加、后趋于平缓,42.1%NS幼苗的净光合速率最高,100%NS次之,3.6%NS的最低,100%NS的幼苗在光合有效辐射1 000μmol/(m~2·s)时净光合速率出现明显下降。42.1%NS条件下光饱和点、表观量子效率、最大净光合速率、气孔导度、平均净光合速率最高,暗呼吸速率和光补偿点相对较低;3.6%NS的所有光合指标均最低;100%NS条件下,光补偿点、暗呼吸速率最高。100%NS的幼苗荧光参数与遮光处理相比,初始荧光显著升高,3.6%NS的可变荧光、最大荧光、PSⅡ原初光能转换效率和PSⅡ潜在活性与其他条件下相比显著降低,42.1%NS和14.3%NS条件下幼苗的叶绿素荧光参数相差不大,也都比100%NS、3.6%NS适宜;表明50%左右的光照条件对幼苗更适宜。
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| 关 键 词： | 大花紫薇Lagerstroemia speciosa (L.)Pers. 光照 光合作用 叶绿素荧光 |
Response of Photosynthetic and Fluorescence Characteristics of Lagerstroemia speciosa Seedlings to Different Light Conditions |
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| Abstract: | Different 1ight environments were simu1ated with shading treatments.100% NS (Natura1 sunshine),42.1%NS, 14.3%NS,3.6% NS. The trends of 1ight response curve of ch1orop1ast pigments content,photosynthesis,ch1orophy11 f1uorescence pa-rameters of Lagerstroemia speciosa(L.) Pers. were measured. The resu1t showed that the contents of ch1orophy11 a, ch1orophy11 b and tota1 ch1orophy11 with decreasing 1ight intensities showed a trend of first increased and then decreased, under 14.3%NS condition were the highest. The va1ue of ch1orophy11 a/b under 100% NS condition were the maximum which is 1.7 times that of the minimum under 14.3% condition. The trends of 1ight response curve of photosynthesis of L. speciosa seed1ings, were simi1iar under three shade conditions,the net photosynthetic rate(Pn) increased rapid1y and then s1ow down fo11ow photo-synthetic active radiation(PAR) enhanced,and Pn under 42.1%NS condition was the highest,then was under 100%NS,that un-der 3.6%NS was the 1owest,Pn under 100%NS condition dec1ined obvious1y when PA R>1 000μmo1/(m2?s). The maximum net photosynthetic rate(Pmax),average net photosynthetic rate (Pa),1ight saturation point (LSP),apparent quantum yie1d (AQY) and the stomata1 conductance (Gs) under 42.1%NS condition were the highest,whi1e the 1ight compensation point (LCP) and the dark respiration rate (Rd) were e1ative1y 1ow. LCP and Rd under 100% NS condition were the highest. A11 photosynthetic in-dexes under 3.6%NS condition were the 1owest. Compared with shade conditions,the f1uorescence parameters basis f1uorescence (F0) under 100%NS seed1ings rose significant1y,the maximum f1uorescence (Fm),variab1e f1uorescence (Fv),potentia1 activity of PSⅡ(Fv/F0) and the efficiency of(Fv/Fm) reduced obvious1y. The f1uorescence parameters under 42.1%NS and 14.3%NS con-ditions had 1itt1e difference. The f1uorescence parameters appeared that the seed1ings under 42.1%NS and 14.3%NS conditions were more suitab1e than those under 100%NS and 3.6%NS condition. A11 these resu1ts indicate that 50% of fu11 1ight condi-tion was most suitab1e. |
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| Keywords: | Lagerstroemia speciosa (L )Pers 1ight intensity photosynthesis ch1orophy11 f1uorescence |
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