[Objective] To study the photosynthesis characteristics and variation law of Korla Fragrant Pear . [ Methods ] Measure the photosynthesis parameters of two type tree shape of Korla Fragrant Pear by Li -6400 and the photosynthetic pigments content and specific leaf weight by experiment methods, discussing the data results. [Result]The results showed that the photosynthetic pigments showed significant differences. The delayed - open central leader shape in content of chlorophyll was significantly higher than that of the open center shape. The total content of chlorophyll changed from 25. 88 mg/cm2 to 38. 96 mg/cm2, but there was no difference in specific leaf weight of different tree shape; The light compensation point of the open center shape and delayed - open central leader shape were 28. 75 μmol/m2 · sand 33. 22 jxmol/m2 · s. The net photosynthetic rate of open center shape was 13. 36 μmol/m2 · s when reaching its light saturation point 109 0 μmol/m2 · s, which was lower than that of delayed -open central leader shape 1 150 μmol/m2 · s; The C02 compensation concentration point of open center shape and delayed - open central leader shape were 63. 55 μmol/mol and 57. 04 μmol/mol, the carboxylation efficiency of both shapes were 0. 039 5 and 0. 036 6. The net photosynthetic rate of open center shape reached its peak value 29. 34 μmol/m · s when CO2 concentration reached 1 135 (xmol/m2 · s. The C02 saturation concentration of delayed -open central leader shape was 1 165 (xmol/m2 · s. [ Conclusion ] The delayed - open central leader shape of light and carboxylation use efficiency was higher than that of the open center shape.
Pyrus bretschneideri RehdThe photosynthetic characteristic parametersphotosynthetic pigmentslight use efficiency