部分桑树品种花粉亚显微形态观察及比较

[目的]了解桑树花粉的亚显微结构及形态学特征。[方法]对7个桑树品种的花粉通过戊二醛固定制样处理,酒精梯度脱水、冷冻干燥和金属喷镀制备后利用扫描电子显微镜进行形态大小及表面纹饰观察。[结果]花粉表面特征及纹饰均清晰可见,表明该试验方法适合桑树花粉的扫描电镜观察;供试桑树花粉为近球形,具2个萌发孔,孔膜具刺突;极轴大小15.99～22.63μm,赤道轴大小14.98～20.78μm,‘育2号’花粉体积最大,而‘晋选7号’花粉最小;花粉外壁均分布有不同密度的点状颗粒,花粉表面呈现平滑和瘤状突起2种纹饰类型。[结论]戊二醛固定液–酒精梯度脱水法是进行桑树花粉形态观察的一种较理想的研究方法;该研究结果或可为桑属植物的孢粉学鉴定及种甚至种下等级的系统分类研究提供有益资料。

Observation and Comparison of Pollen Submicroscopic Morphology of Some Mulberry (Morus alba Linn.) Cultivars

[Objective] This study aimed to investigate the submicroscopic structure and morphological characteristics of mulberry pollen.[Method] Mulberry pollen of seven cultivars were processed by glutaraldehyde fixing,alcohol gradient dehydration,freeze-drying and metal plating to observe the size and surface ornamentation under the scanning electron microscope(SEM).[Result] The pollen surface characteristics and ornamentation were clearly visible,indicating this method is suitable for SEM observation of mulberry pollen;experimental mulberry pollen was nearly spherical,with two germ pores and spike on pore membrane;polar axis was 15.99-22.63 μm,and equatorial axis was 14.98-20.78 μm;the pollen volume of 'Yu No.2' was the maximum,while that of 'Jinxuan No.7' was the minimum;the surface of mulberry pollen showed smooth and tumor-like protuberances ornamentation,covered with different density of particles.[Conclusion] Glutaraldehyde fixative-alcohol gradient dehydration is an ideal method for morphological characteristics of mulberry pollen.This study may provide useful information for palynology identification of Morus plants or even species-level systematic classification.