浙江天台山茶树光合日变化及光响应

自然条件下使用LCA－4型便携式光合测定系统研究了栽培天天台山主峰华顶山的茶树连体叶片的光合日变化及光响应。结果表明：在初夏晴天，上年越冬叶片（下称二年生叶）的光合速率，表观量子效率，羧化效率和饱和光强比展叶红16d的一年生叶高，CO2补偿点和光补偿点比一年生叶低，两者的净光合速率日进程曲线均为“双峰”型，午间胞间CO2浓度上升表明，此时净光合速率下降主要受非气孔限制因素的影响。一年生叶蒸腾速率高于二年生叶，它们日进程曲线为单峰河，午间最高，而气孔阻力进间最低。不同时段作光响应和CO2响应试验表明，上午茶树的表观量子效率，饱和光强和羧化效率较高，光补偿点和CO2补偿点较低。图3表4参26

DIURNAL VARIATIONS OF PHOTOSYNTHESIS AND RESPONSE TO LIGHT OF CAMELLIA SINENSIS LEAVES IN TIANTAI MOUNTAIN IN ZHEJIANG, CHINA

Diurnal variations of photosynthesis and response to light of Camellia sinensis leaves in the Tiantai Mountain in Zhejiang were studied under natural conditions. The results indicated that in early summer sunny days, net photosynthetic rates (A), apparent quantum yield (AQY), carboxylation efficiency (CE) and saturated light intensity in the old leaves from last winter (two-year-old leaves) were higher than those in sixteen-day-old leaves (one-year-old leaves), but CO 2 compensation points and light compensation points of two-year-old leaves were lower. The curves of diurnal variations of A in one-year-old leaves and two-year-old leaves had two peaks, which had an obvious phenomenon of "midday-depression" of A. The rising of the internal CO 2 concentration (C i) at midday indicated that non-stomatal limited elements caused "midday-depression" of A. Transpiration rate (E) in one-year-old leaves was higher than that of two-year-old leaves. The diurnal variations of E had one peak at midday, which was accompanied by the lowest stomatal resistance (r s). The experiments of response of A to light at different time in one day proved that in the morning, AQY and saturated light intensity were high, but light compensation point was low. The response of A to CO 2 concentration showed a higher CE and lower CO 2 compensation point in the morning. Fig 3, Tab 4, Ref 26