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林业科学 ›› 2002, Vol. 38 ›› Issue (4): 34-39.doi: 10.11707/j.1001-7488.20020406

• 论文及研究报告 • 上一篇    下一篇

喜树光合速率日变化及其影响因子的研究

冯建灿 张玉洁   

  1. 河南农业大学,郑州450002;河南省林业技术推广站,郑州450008
  • 收稿日期:2001-10-18 修回日期:1900-01-01 出版日期:2002-07-25 发布日期:2002-07-25

STUDIES ON THE DIURNAL CHANGES OF NET PHOTOSYNTHESIS RATE AND THE EFFECT OF ENVIRONMENTAL FACTORS OF CAMPTOTHECA ACUMINATA

Feng Jiancan,Zhang Yujie   

  1. Henan Agricultural University Zhengzhou450002;Forestry Technique Extending Station of Henan Province Zhengzhou450008
  • Received:2001-10-18 Revised:1900-01-01 Online:2002-07-25 Published:2002-07-25

摘要:

本文对喜树光合速率(Pn)日变化规律进行了研究,结果表明在晴天条件下,喜树Pn日变化为双峰曲线,具有典型的“午休”特征。阴天时则为单峰型。影响喜树叶片Pn日变化的主要生态因子是光通量密度和相对湿度。造成光合作用“午休”的内在原因不是气孔导度下降,减少了CO2 的供应量,而是非气孔因素。

关键词: 喜树, 光合速率, 日变化

Abstract:

Camptotheca acuminata was an important medicinal tree as its camptothecin with anti-tumor activity. The diurnal changes of net photosynthesis rate (Pn) in leaves of C. acuminata under natural condition were studied in this paper by CI-301 CO2 analyzer. The results showed that the curve of diurnal variation of Pn was demonstrated two peaks in clear day, which appeared at 10:00 and 16:00 respectively. The first peak value was 7.9075 μmol CO2·m-2s-1 and the second one was 3.7340 μmol CO2·m-2s-1. There was a clear depression at noon, which was 2.4470 μmol CO2·m-2s-1 appeared at 14:00. Only one peak had the curve of Pn in cloudy day, which occurred at 12:00 Daily average Pn in clear day was 4.3300 μmol CO2·m-2s-1, and that of cloudy was 3.7500 μmol CO2·m-2s-1 Photon flux density (PFD) and relative humidity played very important roles in Pn changes among the ecological factors. Depression of Pn was not caused by the decreasing of stomatal conductance that would decrease the CO2 supply. Factly it was regulated by nostomatal factors.

Key words: Camptotheca acuminata, Net photosynthesis rate, Diurnal variation