植物生态学报 ›› 2007, Vol. 31 ›› Issue (1): 129-137.DOI: 10.17521/cjpe.2007.0016

所属专题: 青藏高原植物生态学:种群生态学

• 论文 • 上一篇    下一篇

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

师生波(), 李和平, 王学英, 李惠梅, 韩发   

  1. 中国科学院西北高原生物研究所,西宁 810008
  • 收稿日期:2006-03-01 接受日期:2006-06-03 出版日期:2007-03-01 发布日期:2007-01-30
  • 作者简介:E-mail: sbshi@mail.nwipb.ac.cn.
  • 基金资助:
    国家自然科学基金(30170154);国际科技合作重点项目计划(2002CB714006);中科院知识创新项目的部分研究内容(KSCX2-1-07)

UTILIZATION AND DISSIPATION OF STRONG SOLAR RADIATION IN TWO ALPINE PLANTS, ANISODUS TANGUTICUS AND RHEUM TANGUTICUM

SHI Sheng-Bo(), LI He-Ping, WANG Xue-Ying, LI Hui-Mei, HAN Fa   

  1. Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xi'ning 810008, China
  • Received:2006-03-01 Accepted:2006-06-03 Online:2007-03-01 Published:2007-01-30

摘要:

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(ΦPSⅡ)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qNm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。NPQSqNs的日变化趋势很相似;同样,NPQFNPQ的主要组分,且唐古特山莨菪的NPQFqNf都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ΦPSⅡ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NPQqN较大,与NPQFqNf以及NPQSqNs都显著大于唐古特大黄有关(p<0.05)。

关键词: 青藏高原, 高山植物, 叶绿素荧光参数, 热能耗散

Abstract:

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 constitutes reversible destruction to PSⅡ reaction center in both alpine plants. Quenching analysis of chlorophyll fluorescence indicated thatA. tanguticus could dissipate more excess excitation energy in PSⅡ antennae through non-photochemistry progress thanR. 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 qNs 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. tanguticum (p<0.05). The fraction of light energy absorbed in PSⅡ antennae, which is utilized in PSⅡ 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 ΦPSⅡ 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.

Key words: Qinghai-Tibet Plateau, alpine plants, chlorophyll fluorescence parameters, thermal dissipation