高山植物唐古特山莨菪和唐古特大黄对强太阳辐射光能的利用和耗散特性
UTILIZATION AND DISSIPATION OF STRONG SOLAR RADIATION IN TWO ALPINE PLANTS, ANISODUS TANGUTICUS AND RHEUM TANGUTICUM

师生波李和平王学英李惠梅韩发

文摘	以西宁地区人工栽培的唐古特山莨菪（Anisodus tanguticus）和唐古特大黄（Rheum tanguticum）为材料，比较研究了两典型高山植物对青藏高原强太阳辐射光能的利用和耗散特性。PSⅡ反应中心的最大光化学效率（Fv／Fm）、实际光化学量子效率（ФPSⅡ）和光合功能的相对限制（L（PDF））的分析表明，强太阳辐射会导致光合作用的光抑制，但并不造成PSⅡ反应中心的不可逆破坏。猝灭分析表明，唐古特山莨菪的光化学猝灭系数（qp）显著小于唐古特大黄，非光化学猝灭（NPQ）和（qN）则相反（P〈0．05），意味着唐古特山莨菪将PSⅡ反应中心吸收的过剩光能以热耗散等非光化学过程消耗的能力大于唐古特大黄，因而降低了用于光化学反应的份额。qN的3组分中，QNf所占比例较大；尽管相对份额很小，中午强光下两高山植物的qNs都有增大趋势，表明它在过剩光能的非光化学耗散中也起重要作用。NPQs和qNs的日变化趋势很相似；同样，MPQF为NPQ的主要组分，且唐古特山莨菪的NPQF和qNF显著大于唐古特大黄（P〈0．05）。唐古特山莨菪PSⅡ天线色素吸收光能中分配于光化学反应的相对份额（P）始终低于唐古特大黄，而用于天线热能耗散的相对份额（D）则大于唐古特大黄，两者都具有极显著差异（P〈0．01）。以上结果表明，唐古特山莨菪的垂PSⅡ较唐古特大黄小是因为PSⅡ天线色素吸收的光能中分配于光化学反应的相对份额或光化学猝灭的比例较小，而分配于天线热耗散的相对份额或非光化学过程的比例较大的缘故。唐古特山莨菪的NPQ和qN较大，与NPQF和qNf以及NPQs和qNs都显著大于唐古特大黄有关（P〈0．05）。
其他语种文摘	Aims The Qinghai-Tibet Plateau is characterized by high elevation, thin atmosphere and high solar transparency. Strong solar radiation is a major stress factors during the growing season. Means of defense and dissipation of strong solar radiation rarely have been explored. Our objective is to determine solar utilization and dissipation characters in two native alpine plants, Anisodus tanguticus and Rheum tanguticum. Methods We used data obtained from a portable pulse amplitude modulation fluorometer （FMS-2, Hansatech Co., UK） to explain the characteristics of utilization and dissipation and components of non-photochemical quenching. Important findings Strong solar radiation could cause the photoinhibition of photosynthesis, but this consti tutes reversible destruction to PS Ⅱ reaction center in both alpine plants. Quenching analysis of chlorophyll fluorescence indicated that A. tanguticus could dissipate more excess excitation energy in PS Ⅱ antennae through non-photochemistry progress than R. tanguticum, as the fraction of energy utilized in photochemistry was decreasing. Dark relaxation kinetics analysis showed that ＂fast＂ component qNf was the main fraction of qN, then ＂slow＂ component qNs. ＂Middle＂ component qNm Was lower than qNs, but it had an increasing tendency accompanied increased light at noon, which indicated that qNm still played an important role in non-photochemical quenching. Diurnal variations of NPQs and qN, were similar in the two plants; the same as qNf, rapidly relaxing quenching NPQF was also the main component in non-photochemical quenching NPQ, and both NPQF and qNf were significantly higher in A. tanguticus than in R. tangutcum （p 〈0.05）. The fraction of light energy absorbed in PS Ⅱ antennae, which is utilized in PS Ⅱ photochemistry （P）, was significantly lower in A. tanguticus than in R. tanguticum （p 〈 0.01 ）, but the fraction that was dissipated thermally （D） was significantly higher in A. tanguticus than in R. tanguticum （p 〈 0.01）. The midday depression of the excess excitation that was neither utilized in photosynthetic electron transport nor dissipated thermally （ Excess ） showed that there was a light stress acclimation in the two alpine plants. The study indicates relatively lower proportion of P and qp in A. tanguticus than in R. tanguticum and the higher fraction of D and NPQ and qN, so actual photochemistry efficiency ФPSⅡ was lower in A. tanguticus than in R. tanguticum. Higher level of NPQ and qN mainly results from the NPQF and qNf, as well as NPQs and qNs in A. tanguticus compared to R. tanguticum.
来源	植物生态学报 ,2007,31(1):129-137 【核心库】
DOI	10.17521/cjpe.2007.0016
关键词	青藏高原 ; 高山植物 ; 叶绿素荧光参数 ; 热能耗散
地址	中国科学院西北高原生物研究所, 西宁, 810008
语种	中文
文献类型	研究性论文
ISSN	1005-264X
学科	植物学
基金	国家自然科学基金 ; 国家科技部国际合作重点项目 ; 中国科学院知识创新工程项目
文献收藏号	CSCD:2734947