四个观赏海棠品种光合特性比较研究

Comparative study on photosynthetic characteristics of 4 varieties of Malus sp.

为比较引种观赏海棠品种间光合特性,以海棠粉芽、红宝石、凯尔斯和绚丽为试材,测定了净光合速率(Pn)、胞间CO2浓度(Ci)、气孔导度(Gs)、蒸腾速率(Tr)等光合生理指标和光响应曲线。结果表明:凯尔斯净光合速率的日变化呈单峰型,但粉芽、红宝石和绚丽的净光合速率的日变化呈双峰型。胞间CO2浓度日变化均呈V型曲线变化,均为早、晚高,中午低;气孔导度日变化曲线为单峰型和双峰型;蒸腾速率日变化曲线均为单峰型,出现峰值时间为10:00—14:00;水分利用效率日变化曲线呈多种类型,均表现为上午高、下午低;凯尔斯的最大净光合速率、光饱和点和表观量子效率最高,绚丽光补偿点最低,红宝石暗呼吸速率最低;4个观赏海棠品种净光合速率平均值为:凯尔斯(8.33μmol·m^(-2)·s^(-1))>绚丽(7.71μmol·m^(-2)·s^(-1))>粉芽(7.29μmol·m^(-2)·s^(-1))>红宝石(5.57μmol·m^(-2)·s^(-1))。综上,凯尔斯光合能力最强,且对光照要求低,可广泛栽植;红宝石光合能力最弱,且对光环境适应性较窄,可作为盆栽海棠新品种;粉芽表现为喜光型,应栽植在光照充足的地区;绚丽具有较强的弱光利用能力,可与其他树种混栽,栽植在光照较弱的地区。

By comparing the differences of photosynthetic characteristics,net photosynthesis rate(Pn),intercellular CO2 concentration(Ci),stomatal conductance(Gs),transpiration rate(Tr)and light photo response curve were determined in four Malus sp.(Pink spire,Ruby,Kelsey,Radiant).The results showed that Kelsey presented single curve in the diunal variation of Pn,while the others were double curve.Diurnal variation of Ci showed as“V”shape,which was high in the morning and evening but low at noon.Diurnal variation of Gs presented single and double curves,and diurnal variation of Tr presented single curves,the highest value appeared at 10:00-14:00.Diurnal variation of WUE presented multiple types.But they were high in the morning and low in the evening.The maximum net photosynthetic rate,light saturation point and surface photon quantum efficiency of Kelsey were the highest,the compensation point of light was the lowest,and the dark respiration rate of Ruby was the lowest.The average net photosynthetic rate of the four cultivars was as follows:Kelsey(8.33μmol·m^(-2)·s^(-1))>Radiant(7.71μmol·m^(-2)·s^(-1))>Pink spire(7.29μmol·m^(-2)·s^(-1))>Ruby(5.57μmol·m^(-2)·s^(-1)).Photosynthetic capacity of Kelsey was the highest,and could be planted with low light requirements.The photosynthetic capacity of Ruby was the weakest and showed weaker adaptability to light environment,which can be used as a new variety for pot culture.Pink spire was photophilic,and should be planted in areas with sufficient light.Pink spire had a certain adaptability to low light intensity,which can be mixed with other tree species in garden application with weak light.