三种金花茶花粉形态的扫描电镜研究

Pollen morphology of three species in sect. Chrysantha studied by scanning electron microscope

关键词:  金花茶, 花粉形态, 电镜, 花粉外壁纹饰, 分类

Key words:  sect. Chrysanthae, pollen morphology, electron microscope, pollen exine sculpture, taxonomy

摘要:

金花茶分类系统尚未完善,金花茶又极具观赏价值,潜在价值极高,该研究应用扫描电镜观察三种金花茶花粉形态,即平果金花茶、直脉金花茶、金花茶,并运用数理统计和图片分析的方法对其花粉形态进行了探讨。结果表明:三种金花茶花粉均属于大花粉粒,花粉平均极轴在50 μm以上,花粉极面观为钝凹三角形,萌发孔为三孔沟,即N₃P₄C₅类型。平果金花茶与直脉金花茶花粉外壁纹饰为拟网状纹饰,平果金花茶网眼较密,网脊稍不平,直脉金花茶网脊稍隆起; 金花茶为蠕虫状纹饰,短条状突起。花粉形态对其分类有重要意义,通过花粉外壁纹饰的类型可知金花茶与其二者亲缘关系较远,花粉形态各指标具有种间变异性,种内具有保守性,而平果金花茶和直脉金花茶花粉外壁纹饰相同但具体分类还需进一步研究。该研究结果为金花茶种质资源分类和利用提供了参考,在一定程度上促进了金花茶资源的开发和利用。

Abstract:

Pollen grains from 3 species of sect. Chrysantha were examined using the scanning electron microscope, including Camellia pingguoensis, C. multipetala var. patens, C. chrysantha. The characteristics of pollen morphology among the species were distinguished using data statistics and photographic analysis. The pollens were large pollen grains, mean polar axis pollen size in the three species was over 50 μm, blunt concave triangle in polar view. According to morphological photography, the aperture were three hole groove, namely N₃P₄C₅ type. Two basic sculpes were defined: tuberculate-baculate, viz, ornate. C. pingguoensis, C. multipetala var. patens were the latter, C. chrysantha was the other. C. pingguoensis relatively dense mesh, mesh ridge slightly rough, C. multipetala var. patens net ridge slightly uplift, C. chrysantha short strip projections. Pollen morphology has important significance for its classification, through the pollen exine sculpture type, C. chrysantha with C. pingguoensis, C. multipetala var. patens were more distant relatives. Pollen morphology had variability among species, had conservation within species, but the classification of C. pingguoensis and C. multipetala var. patens still need further study. By comparing the pollen size, shape, the exine pore characteristics and morphological indexes etc, the results showed that there was an obvious similarities and differences of three species of sect. Chrysantha pollen morphology but sect. chrysantha set classification is complex, not only from the palynology into consideration, has a long way for sect. Chrysantha set classification. Sect. Chrysantha found up to now, enjoyed a good reputation at home and abroad, has been enjoying by botanists, horticulturalist, but its classification system is not yet clear. In fact, classification system has been being improved, sect. Chrysanthae has ornamental value and highly potential value. The results provide sect. chrysanthae germplasm resources classification and the use of value, promote sect. Chrysanthae development of resource utilization.