温度和光照对‘红地球’葡萄试管苗光合特性的影响

 以‘红地球’葡萄(Vitis vinifera L. ‘Red Globe’) 试管苗为试材, 采用密闭系统落差法研究了在不同温度和光照强度下培养28 d的试管苗的光合特性。结果表明: 培养温度在20～30 ℃之间, 试管苗的暗呼吸速率(Rd ) 随温度的升高而升高, 但净光合速率( Pn ) 以25 ℃最高, 30 ℃次之, 20 ℃最低;而CO₂补偿点以25 ℃最低, 20 ℃次之, 30 ℃最高; 光照强度在40～200μmol·m ^-2 ·s^-1之间, 葡萄试管苗的P_n随光照强度( PAR) 的升高而升高, CO₂补偿点随PAR的升高而降低。在光照条件下, 容器内CO₂浓度迅速降低, 并接近CO₂补偿点, CO₂供应不足是影响试管苗同化能力的主要原因。在室内培养阶段,采用弱光、昼夜变温和改善培养容器的通气性有利于提高试管苗的光合能力; 在移栽驯化过程中, 逐步提高光照强度和延长光照时间有利于试管苗同化产物的积累和培养壮苗。

Effects of Temperature and Light Intensity on Photosynthetic Characters of 'Red Globe' Grape Plantlet in Vitro

By the ways of falling and airproofing, the research was made on the photosynthetic characters of grape (Vitis vinifera L. ‘Red Globe’) p lantlets in vitro cultivated under different temperatures and photosynthetic availability radiations ( PAR). The results showed that under the temperatures between 20 ℃ and 30 ℃, the dark resp iration rate (Rd ) rose with the rise of the temperature, while the net photosynthesis rate(Pn) reached the highest in 25℃, slowed in 30 ℃, and reduced to the lowest in 20 ℃. However, the compensation point of CO₂ was the lowest in 25 ℃, rose in 20 ℃, and reached the highest in 30 ℃. When the PAR was between 40 and 200μmol·m^-2 ·s^-1 , the P_n of the grape p lantlet rose with the increase of PAR,while the compensation point of CO₂ decreased with the increase of the PAR. When PAR was available, the concentration of CO₂ in the vessel reduced rap idly, almost close to the compensation point of CO₂. The insufficient supp ly of CO₂ is the chief factor that affects the assimilation of the plantlets. In the stage of indoor cultivation, the weak light, temperature changes by day and night and the imp rovement of the ventilation of the cultivated vessels are advantageous to imp roving the photosynthesis of the plantlets. And in the process of transplantation and domestication, the gradual increase and extension of the light are advantageous to accumulating the products of the plantlet assimilation and generating the strong plantlets.