不同枇杷品种光合作用特性研究

在田间自然条件下对3个从日本引进的枇杷良种(3号、8号和9号)和1个当地主栽良种(4号)的 光合特性进行了比较研究。结果表明,在晴天和阴天,4个枇杷品种叶片的净光合速率(Pn)日变化均呈双峰曲线, 具有典型的“午休”特征;阴天时4个枇杷品种的Pn均比晴天时高。阴天时除9号品种外,其他3个品种的蒸腾速 率(Tr)日变化呈双峰曲线;晴天时除3号品种的Tr日变化呈双峰曲线外,其他3个品种均为单峰曲线。4个枇杷 品种细胞间CO2浓度的升降并不完全受气孔导度的影响,造成晴天和阴天出现光合“午休”现象的内在原因主要是 非气孔因素。晴天和阴天均以9号品种的日均水分利用率最高,表明9号枇杷品种最耐旱。

Comparative study on photosynthetic characteristics of different loquat varieties

The photosynthetic characteristics of 3 different loquats introduced from Japan were studied in comparison with a local variety under natural condition. The curves of diurnal variation of net photosynthesis rate (Pn) showed two peaks under clear and cloudy day. There was a clear depression at noon;The Pn at cloudy day was higher than that at clear day. The curves of diurnal variation of transpiration (Tr) of 3 species showed two peaks under cloudy day except No. 9;but the curves of diurnal variation of transpiration (Tr) of 3 species showed one peak under clear day except No. 3. Depression of Pn was caused by noncommittal factors. The No. 9 Loqaut was the highest in drought resistance.