'秦冠'苹果花粉培养及微丝骨架的变化

以'秦冠'苹果花粉为试材,采用花粉离体培养法,研究了不同培养基组分以及温度对苹果花粉萌发的影响.结果表明:(1)蔗糖和硼酸在一定质量浓度范围内,对苹果花粉萌发及花粉管生长起促进作用,但超过一定质量浓度时则起抑制作用.秦冠苹果花粉最适的培养基为20%蔗糖和0.01%硼酸,花粉的萌发率可以达到60%.在此基础上,以Alexa Fluor 488phalloidin作为肌动蛋白微丝的探针,运用激光共聚焦显微镜技术,观察了苹果花粉萌发过程中微丝骨架的分布变化动态;(2)在未水合的苹果花粉粒中,均匀分布着短小弯曲、颗粒环形微丝.在水合而未萌发的的花粉中,微丝呈网状分布在胞质中,萌发沟部分肌动蛋白束网络较致密,中央胞质部分较疏松.花粉萌发后,微丝转变为平行排列,向花粉管伸长的方向延伸聚集,与花粉管纵向平行排列;(3)生长异常的花粉管内其微丝状态也异常.

Culture of 'Qinguan' apple pollen and dynamic of actin filaments

'Qinguan' apple pollen was chosen as the material to study the effect of culture medium composition on pollen germination by in vitro liquid culture method. Results illustrated that sucrose and H3 BO3 promoted the pollen germination and tube growth, but this function was reversed if overrun certain concentration. Moreover,the effects of calcium were unapparent. The optimal culture medium was 200 g/L sucrose and 10 mg/L boric acid,in which the rate of pollen germination was up to 60%. Alexa Fluor 488 phalloidin was chosen as a probe of actin filaments to observe the changes of actin filament in the process of apple pollen germination by the confocal laser scanning microscopy. In unhydrated pollen, short bending or ring particles of microfilaments were observed. In the hydrated and ungerminated pollen, dense actin filament was detected in the cytoplasm. When the pollen began to germinate, actin filament bundles in the pollen grain arranged pointing towards the tube. In the elongated tube, actin filament bundles were mainly in the middle and front region of pollen tube, but there were no obvious actin filaments in the tip of pollen tube. Abnormal actin filaments were detected in abnormal pollen tube.