两种叶型五指毛桃的光合特性比较研究

Comparative Study on Photosynthetic Characteristics of Two Leaf Types of Ficus hirta Vahl.

关键词:  圆叶五指毛桃  缺叶五指毛桃  净光合速率  光响应曲线  光合日变化

Key words:  undivided Ficus hirta Vahl.  partited Ficus hirta Vahl.  net photosynthetic rate  light response curve  diurnal variation of photosynthesis

摘要:

五指毛桃（Ficus hirta Vahl.）具有较高的遗传多样性。本研究对野外引种的两种叶型五指毛桃的光合特性进行比较，为进一步了解和利用五指毛桃提供科学依据。以圆叶五指毛桃和缺叶五指毛桃为试材，采用LI-6400便携式光合测量仪测定两种五指毛桃的叶片光合作用参数，并对其净光合速率与主要环境因子进行相关性分析。圆叶五指毛桃最大净光合速率为4.89 μmol·m^-2·s^-1，显著高于缺叶五指毛桃（P<0.05），高出12.10%；圆叶五指毛桃的表观量子效率、光饱和点、光补偿点分别为0.044，1 046.89和25.17 μmol·m^-2·s^-1，缺叶五指毛桃的分别为0.036，1 400.70和17.37 μmol·m^-2·s^-1。两种不同叶型五指毛桃叶片净光合速率日变化均呈现“双峰型”曲线，出现光合“午休”现象，均主要为气孔限制因素所致，圆叶五指毛桃净光合速率日变化均值比缺叶五指毛桃高36.70%。圆叶五指毛桃最大净光合速率值较大，同时具有较低的光饱和点及较高的光补偿点；缺叶五指毛桃最大净光合速率值较小，具有较高的光饱和点及较低的光补偿点。缺叶五指毛桃的光照适应范围较圆叶五指毛桃广，可种植范围更大，在选用两种进行间种或林下套种时，应注意适当增大株行距，同时注意通光。

Abstract:

Ficus hirta Vahl.has high genetic diversity.The purpose of this study was to compare the photosynthetic characteristics of two different leaf types of F. hirta Vahl.introduced in the field, aiming to provide scientific basis for further understanding and utilization of F. hirta Vahl..The photosynthetic parameters of the undivided and the partited F. hirta Vahl.were measured by LI-6400 portable photosynthesis instrument, and the correlation between the net photosynthetic rate and the main environmental factors was analyzed.The maximum net photosynthetic rate of the undivided F. hirta Vahl.was 4.89 μmol·m^-2·s^-1, which was 12.10% higher than that of the partited F. hirta Vahl.(P<0.05).The apparent quantum efficiency, light saturation point and light compensation point of the undivided F. hirta Vahl.were 0.044, 1 046.89 and 25.17 μmol·m^-2·s^-1, respectively.The apparent quantum efficiency, light saturation point and light compensation point of the partited F. hirta Vahl.were 0.036, 1 400.70 and 17.37 μmol·m^-2·s^-1, respectively.The diurnal variation of net photosynthetic rate of the two different leaf types of F. hirta Vahl.showed a "bimodal" curve, and the phenomenon of photosynthetic "midday depression" was mainly caused by stomatal limiting factors.The average diurnal variation of net photosynthetic rate of undivided F. hirta Vahl.was 36.70% higher than that of partited F. hirta Vahl.The maximum net photosynthetic rate of undivided F. hirta Vahl.was higher, with lower light saturation point and higher light compensation point, while the maximum net photosynthetic rate of partited F. hirta Vahl.was lower, with higher light saturation point and lower light compensation point.The light adaptation range of partited F. hirta Vahl.was wider than that of undivided F. hirta Vahl., and the planting range was larger.At the same time, when choosing two types of intercropping or inter-planting under the forest, attention should be paid to appropriately increase the row spacing of plants and maintain light access.