海南油茶5个无性系光合特性比较研究

Comparative study on photosynthetic characteristic of 5 Camellia oleifera clones in Hainan province

为了研究海南油茶光合效率的高低及不同无性系之间光合特性的差异,筛选高光效的海南油茶无性系,以初步筛选的5个油茶优良无性系‘海南2号’、‘海南6号’、‘海南9号’、‘海南18号’和‘海南19号’为试材,利用Li-6400xt便携式光合作用测定系统,测定了其光合作用日变化及光合-光响应曲线和光合-CO_2响应曲线,结果表明:‘海南2号’的净光合速率日变化呈单峰曲线,其它4个油茶无性系的净光合速率日变化呈双峰曲线;‘海南18号’的蒸腾速率呈单峰曲线,其它4个油茶无性系的蒸腾速率呈双峰曲线,峰值分别出现在9:00和15:00;‘海南18号’和‘海南2号’气孔导度的日变化呈单峰曲线,‘海南9号’、‘海南19号’及‘海南6号’的日变化与Pn的日变化相一致;‘海南2号’的光饱和点和光补偿点最低,‘海南19号’的光饱和点和光补偿点最高;5个油茶无性系的CO_2补偿点较高,具有C3植物的光合特性;5个无性系Pn日变化的平均值由高到低顺序为‘海南19号’>‘海南18号’>‘海南9号’>‘海南2号’>‘海南6号’;相关分析表明,影响Pn的主要生理生态指标大小顺序依次为气孔导度>光合有效辐射>蒸腾速率>胞间CO_2浓度。

In order to study high and low of photosynthetic efficiency and differences of photosynthetic characteristics between different clones of Camellia oleifera in Hainan, screening of high photosynthetic efficiency of clones of Camellia oleifera in Hainan province. The photosynthesis diurnal changes, photosynthetic-light response curve and photosynthetic-CO2 response curve for net photosynthetic rate of 5Camelliaclonesinhainan： ＇Hainan2＇ , ＇Hainan6＇ , ＇Hainan9＇ , ＇Hainanl8＇ and ＇hainanl9＇ were measured with Li-6400 photosynthetic instrument under field conditions. The results showed that： Net photosynthetic rate （Pn） of ＇Hainan 2＇ changed as single peak curve, while other four kinds of clones in the diurnal variation of net photosynthetic rate were changed as double- peak curve; Transpiration rate （Tr） of ＇Hainan 18＇ changed as single peak curve, while other four kinds of clones in the diurnal variation of net photosynthetic rate were double-peak curve, and the peak appear at 9：00 am or at 15：00 pm; Stomatal conductance （Gs） of ＇Hainan 18＇ and ＇Hainan 2＇ changed as single peak curve, while ＇Hainan 9＇ , ＇Hainan 19＇ and ＇Hainan 6＇ had same change as net photosynthetic rate; The light compensation points and light saturation points of ＇Hainan 2＇ were the highest while ＇Hainan 19＇ were the lowest in five Camellia oleifera clones in Hainan. The CO2 compensation point of 5 Camellia oleifera clones in Hainan was high, consistent with the photosynthetic characteristics of C3 plants. The order in daily change of average net photosynthetic rate of 5 Camellia oleifera clones taken as ＇Hainan 19＇ 〉 ＇Hainan 18＇ 〉 ＇Hainan 9＇ 〉 ＇Hainan 2＇ 〉 ＇Hainan 6＇ .The impact order that main ecological physiological of net photosynthetic value of 5 Camellia oleifera clones was stomatal conductance 〉 photosynthetic active radiation 〉 transpiration rate 〉 intercellular CO2 concentration.