高山杜鹃品种光合特性比较

Comparative Study on Photosynthetic Characteristics of the Rhododendron delavayi Cultivars

对红粉玉蝶、井岗紫霞等5个从河北石家庄等地引进的高山杜鹃优良品种的主要光合生理指标、光合日变化进行了比较研究,并对各品种的光响应曲线进行了拟合。结果表明:不同品种的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、水分利用率(WUE)和光饱和点(LSP)之间的差异明显,各品种的光补偿点(LCP)均较低;净光合速率的日变化也存在明显的品种间差异,有3个品种呈"中午降低型"的双峰曲线,2个品种呈单峰曲线。品种红粉玉蝶、井岗紫霞具较高的净光合速率、蒸腾速率和气孔导度,表现出较高的光合作用能力和生产潜力;同时这2个品种又有较低的光补偿点和较高的光饱和点,表现出较强的弱光利用能力和强光利用潜力。因此,从光合特性角度考察,这2个品种适宜在江苏省推广种植。

Photosynthetic physiology index and diurnal change of photosynthesis, in 5 Rhododendron delavayi cuhivars , such as jean de marle montague, Bule bell, which were introduced from Shijiazhuang, Hebei Province were studied. The photosynthetic light -response curve of different cuhivars was also simulated. The results showed that net photosynthetic rate （ Pn ）, transpiration rate （ Tr ）, stomatal conductance （ Gs ）, intracellular concentration of CO2 （ Ci ） , water use efficiency （WUE） of cuhivars and the light saturation point in leaves of 5 cuhivars were different and had obvious differences, and the light compensation point was similar. Diurnal change of net photosynthetic rate among cultivars were different, three eultivars showed twin-peaked curve with an obvious midday-depress, others showed single peak curves. Jean de marie montague and bule bell had high net photosynthetic rate（ P, ）, transpiration rate（ Tr ）and stomatal conductance（ Gs ）, and showed high photosynthetic and potential productivity. The two cuhivars also had low light compensation point and high light saturation point, showed high capacity for using light. Based on the photosynthetic characteristics, the two Rhododendron delavayi cultivars are suited to growing in Jiangsu Province.