---

作 者 ：尤鑫,龚吉蕊*,段庆伟,葛之葳,闫美芬,张新时

期 刊 ：生态学报 2008年 28卷 11期 页码：5641~5648

关键词：光化学淬灭；非光化学淬灭；叶绿素荧光参数；热耗散；

Keywords:photochemical quenching, non-photochemical quenching, chlorophyll fluorescence parameters, thermal dissipation,

摘 要 ：比较研究伊犁地区两种典型杨树苗大叶杨（大叶钻天杨P.balsanifera Linn(Da)）和伊犁杨5号（P.euramerieana cv(I-467)）对太阳辐射光能的利用和耗散特性。光照条件下光合系统Ⅱ反应中心（PSⅡ）的最大光化学效率（Fv′/Fm′）、实际光化学效率（ΦPSⅡ）和光合功能的相对限制 (L(PDF)) 的分析表明，高的光合有效辐射强度（PAR）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。淬灭分析表明，Da的光化学淬灭系数（qP）大于I-467，非光化学淬灭 (NPQ) 则相反（p< 0.05）。Da的NPQ显著小于I-467的，意味着I-467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Da，因而相应降低了用于qP的份额。两种杨树的NPQ日变化趋势很相似；Fv′/Fm′和ΦPSⅡ的日变化趋势相似。Da的PSⅡ天线色素吸收光能中分配于光化学反应平均的相对份额（P）高于I-467，在较低的PAR环境中Da比I-467能更好的利用光能；Da用于天线热能耗散的相对份额（D）则小于I-467，两者具有极显著差异（p< 0.01）。Da的ΦPSⅡ比I-467大，是因为PSⅡ天线色素吸收的光能中分配于P或光化学淬灭的比例较大，而分配于D或非光化学过程的比例较小的缘故，反应中心的ΦPSⅡ也较Da小。在有效的利用光能方面，Da比I-467更适宜在新疆伊犁地区大面积推广栽植。

Abstract:Our objective is to determine solar utilization and dissipation characteristics in two introducing and widely planted poplar, P.balsanifera Linn (Da) and P.euramerieana cv(I-467) in the Ili Autonomous Prefecture characterized by poplar high-production and high solar radiation. We used a portable LCF (Li-6400, LI-COR, US) to explore the characteristics of two poplar seedlings utilization, dissipation of photochemical quenching and non-photochemical quenching. Strong solar radiation could cause the photoinhibition of photosynthesis, but this constitutes reversible destruction to PSⅡ reaction center in both plants. The study indicates there are the relatively lower net photosynthesis (Pn) and photochemical quenching (qP) in I-467 than in Da and the higher NPQ, so actual photochemistry efficiency ΦPSⅡwas higher in Da than in I-467. The NPQ is higher for I-467 compared to Da. Chlorophyll fluorescence Quenching analysis indicated that Da could use more solar energy utilized to qP than I-467, but I-467 could dissipate more excess excitation energy in PSⅡantennae through non-photochemistry progress than Da, as the fraction of energy utilized in photochemistry decreasing. Diurnal variations of Fv′/Fm′ and ΦPSⅡwere similar in the two plants, as NPQ was the main component in non-photochemical quenching, and both were higher in I-467 than Da (p<0.05). The fraction of light energy absorbed in PSⅡ antennae was lower in I-467 than in Da (p<0.01), but the fraction that was dissipated thermally (D) was significantly higher in I-467 than in Da (p<0.01) under the low radiation. The excess excitation after midday (Excess) was declined in the two plant seedlings. Da is more adaptive than I-467 to plant in Ili Autonomous Prefecture for solar energy utilization.

---