北沙参花粉形态特征、活性及萌发条件研究

Study on Pollen Viability and Morphological Characteristics of Glehnia littoralis

为了认识北沙参的花粉粒形态特征和生理特性,利用离体培养法测定花粉粒活性,并对培养条件(蔗糖的质量分数、硼酸的质量浓度和氯化钙的质量浓度)进行筛选,同时与碘-碘化钾(I2-KI)、氯化三苯基四氮唑(TTC法)和亚甲基蓝等花粉活性测定方法进行比较,建立测定北沙参花粉活性的最适宜方法,利用离体培养法进一步检测保存时间、温度和湿度等对北沙参花粉活性的影响,应用扫描电镜观察花粉粒的大小形态等特征。结果表明,亚甲基蓝法适于北沙参花粉粒活性测定,I2-KI法和TTC法不适合。北沙参体外萌发的最适培养基是20%蔗糖+0.1%mg·mL^-1硼酸+0.1%mg·mL^-1氯化钙,萌发率可达72.9%。北沙参花粉在湿度15%~52%,25℃条件下活性最好,4℃、-20℃的低温或大于60%的湿度都会导致花粉活性降低。北沙参花粉粒形态为超长方形,具3个狭长萌发沟,表面为网状。

Objective: to investigate the pollen morphological and physiological characteristics of Glehnia littoralis(beishashen).Methods: the pollen grain viability was searched using an in vitro method and the optimal concentration of sucrose, H3BO3 and CaCl2 on pollen germination. it contrasted with the I2-KI, TTC and Methylene blue(MB) methods to find the proper determination method for pollen vitality. And then it was studied that the effect on pollen grain viability under the different storage time and temperature and humidity. Pollen morphology was studied by scanning electron microscopy(SEM). Results: Methylene blue method was suitable for the determination of pollen grain activity of Glehnia littoralis, I2-KI and TTC methods were not.The optimal medium was 20% sucrose+0.1 mg·mL^-1 H3BO3+0.1 mg·mL^-1 CaCl2 on pollen germination in vitro and the pollen germination ratio was up to 72.9%. Pollen viability was the highest in 24 h and it could keep about 10 d in 25 ℃ environments. The pollen grains were 3-colpate prolate, with reticulate ornamentation.Conclusion: The methods and storage conditions for the determination of pollen grain activity were preliminarily established, and the morphological characteristics of the pollen were understood, which laid a foundation for the breeding of the improved varieties of Glehnia littoralis.