Department of Horticulture and Landscape Architecture, Washington State University, Pullman, Washington 99164-6414.
Plant Physiol. 1985 Jul;78(3):519-24. doi: 10.1104/pp.78.3.519.
Seasonal changes in photosynthesis of apple trees (Malus domestica Borkh.) were monitored to examine the effect of source-sink interactions on photosynthesis and photorespiration. Elevated photosynthetic rates were observed during two periods of the growing season and correlated with the fruiting process. The first period of increased photosynthetic rates was during the bloom period, when spur leaves on flowering shoots exhibited up to 25% higher photosynthetic rates than vegetative spur leaves on a leaf area basis. CO(2) assimilation rates were also higher in fruiting trees than nonfruiting trees during the period of rapid fruit growth from July to September. Photorespiration, dark respiration, leaf resistance, and transpiration exhibited no seasonal changes which correlated to the presence or absence of fruit. These data represent the first comprehensive examination of the effects of flowering/fruit formation on photosynthesis and photorespiration in perennial plants.
苹果树（Malus domestica Borkh.）的光合作用具有季节性变化，本研究旨在探讨源库关系对光合作用和光呼吸的影响。结果表明，在生长季节中有两个时期的光合作用速率较高，并且与果实发育过程相关。第一个高光合速率时期出现在开花期，此时开花枝上的短果枝的光合速率比叶面积相同的营养短果枝高 25%。7 月至 9 月果实快速生长期间，与未结果实的树相比，结果实的树上的 CO2 同化率也更高。光呼吸、暗呼吸、叶片阻力和蒸腾作用在有果实和无果实的情况下均无季节性变化。这些数据代表了首次对开花/果实形成对多年生植物光合作用和光呼吸影响的全面研究。
