套种不同作物对油茶光合特性的影响

Effect of Interplanting Crops on Photosynthetic Characteristics of Camellia oleifera

利用Li-6400便携式光合测定系统对油茶套种旱稻、油茶套种中药材、油茶单作3种处理下‘长林4号’油茶无性系的光合作用日变化以及光响应曲线进行测定。结果表明:3种处理下的油茶净光合速率(Pn)日变化均呈典型的双峰曲线,有明显的光合午休现象,9:00-10:00达到最大值;3种处理下的油茶蒸腾速率(Tr)、气孔导度(Gs)日变化规律与净光合速率的日变化规律基本相同,亦呈双峰曲线,而胞间二氧化碳浓度(Ci)的日变化进程大致呈"V"型;套种旱稻、套种中药材、单作处理的油茶光补偿点分别为8、11和14μmol·m-2·s-1,光饱和点分别为792、748、664μmol·m-2·s-1,这表明3种处理下的油茶对光强的适应范围大小为套种旱稻>套种中药材>油茶单作;非直角双曲线拟合后套种旱稻、套种中药材、单作处理的油茶最大净光合速率分别为13.3、12.3、10.6μmol·m-2·s-1,说明在高光条件下,套种旱稻和中药材都能提高油茶的光合能力。

The diurnal variation of photosynthesis and light response curves ofCamellia oleifera interplanted with different crops Changlin 4’ were measured by Li-6400 portable photosynthetic system. The results showed that Pn diurnal variation of 3 different treatments was typically double-peak curve with the highest peak at 9：00 - 10：00 am and had ‘Midday depression’. The diurnal variation of Tr and Gs of 3 different treatments was similar to Pn, showed double-peak curve, but the diurnal variation of Ci showed nearly ‘V’ curve. The light compensation points was 8, 11, 14μmol·m^-2·s^-1 by interplanting upland rice, traditional Chinese medicines.and 14μmol·m^-2·s^-1 in monoculture ofC. oleifera, while light saturation points were 792, 748 and 664μmol·m^-2·s^-1 respectively. The experiments demonstrated that the maximum Pn ofC. oleifera interplanted with upland rice, traditional Chinese medicine andmonoculture was 13.3, 12.3 and 10.6μmol·m^-2·s^-1 respectively, indicating that interplanting upland rice and traditional Chinese medicine could improve the photosynthetic ability ofC. oleifera.