吐鲁番盆地两个杏品种光合响应特征研究

Photosynthetic Response Characteristics of Two Apricot Varieties in Turpan Basin

在吐鲁番托克逊县早熟杏种植区域,以两个主栽品种‘苏勒坦’和‘小白杏’为试材,采用Li-6400便携式光合仪测定气体交换参数,并利用非直角双曲线模型和直角双曲线模型分别拟合光响应曲线和CO2响应曲线,分析两个品种光合特征参数的差异。随着光照强度的增加,两个品种的净光合速率、气孔导度和蒸腾速率均有不同程度的增加,瞬时水分利用效率先升高后降低,而胞间CO2浓度明显降低;‘苏勒坦’的最大净光合速率相较‘小白杏’的最大净光合速率高7.57%、光饱和点高24.94%、表观量子效率高50.00%。两个杏品种的净光合速率随CO2浓度的增加迅速升高,且在本试验设定的CO2浓度梯度下均未出现CO2仰制现象。‘苏勒坦’的羧化效率较‘小白杏’的羧化效率高24.13%,且其CO2饱和点较‘小白杏’的CO2饱和点高18.39%、最大净光合速率高7.40%。‘苏勒坦’利用强光的能力较强,碳同化能力也较强,气孔控制比较灵敏,光强过高时,它通过降低气孔导度,降低蒸腾耗水,提高水分利用效率,对吐鲁番盆地高温、强光、干旱生长环境表现出较好的适应能力。

Two main cultivars‘Suletan’and‘Xiaobaixing’were used as test materials.The gas exchange parameters were measured by Li-6400 portable photosynthetic system in the apricot planting area in Toksun County,Turpan,and the light response curve and CO2 response curve were fitted by non right angle hyperbolic model and right angle hyperbolic model respectively.After that,the differences of photosynthetic characteristic parameters between the two cultivars were analyzed.With the increase of light intensity,the net photosynthetic rate,stomatal conductance and transpiration rate of the two varieties increased to varying degrees.The water use efficiency increased first and then decreased,while the intercellular CO2 concentration decreased significantly;The maximum net photosynthetic rate,light saturation point,apparent quantum yield of‘Suletan’were 7.57%,24.94%and 50.00%higher than those of‘Xiaobaixing’respectively.The net photosynthetic rate of two apricot varieties increased rapidly with the increase of CO2 concentration,and there was no CO2 inhibition under the CO2 concentration gradient set in this test.The carboxylation efficiency,CO2 saturation point,maximum net photosynthetic rate of‘Suletan’were 24.13%,18.39%and 7.40%higher than those of‘Xiaobaixing’respectively.‘Suletan’had stronger ability to utilize the strong light,a strong ability to assimilate carbon,and a sensitive stomatal control mechanism.When the light intensity was too high,the stomatal conductance and the water consumption could be reduced so that the water use efficiency was improved,which had good adaptability to the extremely high temperature,strong light and dry planting environment in Turpan Basin.When the light intensity is too high,it reduces stomatal conductance,reduces transprational water consumption and improves water use efficiency.