贵州中部地区苹果的光合特性及其对产量和品质的影响

 以贵州中部地区4年生‘红富士’和‘皇家嘎啦’苹果品种为试材，探索了树冠不同层次、部位叶片的光合特性、影响光合速率（Pn）的主要环境因子及Pn与产量和品质的关系。结果表明，‘红富士’的光合能力（14.87 μmol · m-2 · s-1）强于‘皇家嘎啦’（13.57 μmol · m-2 · s-1）；两品种的Pn日变化曲线均呈双峰型，出现午休现象，其主要成因为中午的高光强（PAR）及气孔导度（Gs）下降；Pn受PAR影响最大，叶温（Tl）次之，而大气相对湿度（RH）和空气CO2浓度影响不大；树冠的PAR及Pn对果实产量及外观有重大影响，单果质量、可溶性糖含量、糖酸比等品质指标与PAR及Pn呈显著正相关，而PAR及Pn对维生素C含量的作用不明显。

The Photosynthetic Characteristics of Apple and Their Effects on Fruit Yield and Quality in Middle Guizhou Province

To provide the physiological basis for apple in middle Guizhou Province, the photosynthetic characteristics, main factors impacting photosynthetic rate（Pn），as well as their effects on fruit yield and quality were elucidated in the present work. The results showed that‘Red Fuji’（14.87 μmol · m-2 · s-1） demonstrated a superior photosynthetic ability to‘Royal Gala’（13.57 μmol · m-2 · s-1）. They exhibited diurnal fluctuations of Pn with two peaks in the summer, and an obvious midday depression was observed in both cultivars, which was primarily ascribed to the excessive photosynthetically active radiation（PAR）and reduced stomatal conductance（Gs）. Photosynthesis was most predominantly affected by PAR, followed by the leaf temperature（Tl），and were slightly influenced by relative humidity（RH） and air CO2（Ca）. The yields of two cultivars were highly correlated to PAR and Pn. The quality parameters，including fruit weight，soluble sugar content, and sugar acid ratio，were positively correlated with PAR and Pn，with the exception of vitamin C content. Based on the photosynthetic features, some technical measures on apple cultivation in the middle of Guizhou were put forward to promote light use efficiency.