Photosynthesis by flowers in Encelia farinosa and Encelia californica (Asteraceae)
Photosynthesis by flowers in Encelia farinosa and Encelia californica (Asteraceae)
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Encelia farinosa 和 Encelia californica（菊科）花朵的光合作用
作者：
K. Werk;J. Ehleringer
摘要研究了灌木 Encelia farinosa 和 E. californica 在花朵发育的三个物候阶段的花朵的光合速率。花中的总光合作用和暗呼吸速率相似，并且随着花的发育而降低。花卉光合速率在相当于半个正午阳光的辐照度下达到饱和。花的净光合作用很少为正值，并且随着花温的升高而大幅下降。花的气体交换不受水蒸气压力梯度的影响。这些结果根据花卉所经历的小气候以及花卉光合作用对花卉经济的相对贡献进行了分析。
SummaryPhotosynthetic rates by flowers of the shrubs Encelia farinosa and E. californica were studied during three phenological stages of flower development. Both gross photosynthesis and dark respiration rates in the flowers were of similar magnitude and decreased with floral development. Floral photosynthetic rates were saturated by an irradiance equivalent to one half full noon sunlight. Net photosynthesis of flowers was rarely positive and decreased substantially with increased flower temperature. Gas exchange by the flower was unaffected by the water vapor pressure gradient. These results are analyzed in terms of the microclimate experienced by the flowers and the relative contribution of floral photosynthesis to the economy of the flower.