睡莲属植物花粉形态研究

Studies on Pollen Morphology of Nymphaea

为明确睡莲属植物花粉形态特征,研究利用扫描电镜对18种或品种睡莲属植物的花粉形态特征进行观察,并对花粉形态及其种间亲缘关系进行分析,同时利用离体萌发法对睡莲品种‘彼得’的花粉活力进行测定,为睡莲杂交育种亲本的选择提供依据。结果表明:(1)18种或品种睡莲属植物的花粉均为单粒花粉,形态均为近球体或扁球体,其中巨花睡莲花粉粒最大,体积指数为30.3;埃及白睡莲花粉粒最小,体积指数为19.2。(2)花粉外壁纹饰类型繁多,包括网纹状、小颗粒状、瘤状、小柱状、长条状、微波纹起伏状。(3)根据聚类分析可将18种或品种睡莲属植物分为4个类群,其中Nymphaea亚属与Brachyceras亚属间亲缘关系最近。(4)‘彼得’的花粉离体萌发率高,可达95%以上。研究认为,睡莲属植物的花粉形态特征,特别是花粉萌发沟类型、外壁纹饰等特征可作为睡莲属植物种间分类、亚属间以及种间亲缘关系、系统进化规律的关键证据。

In order to clarify the morphological characteristics of the Nymphaea pollen,the morphological characteristics of 18 species or cultivars of Nymphaea were observed by scanning electron microscopy in this study.The pollen morphological characteristics and relationships between subgenera and species were analyzed,and the pollen viability of the N.‘Peter Slocum’was investigated by in vitro germination method.The study provides a basis for selecting parents for hybrid breeding of Nymphaea.The results showed that:(1)The pollen of 18 species or cultivars in Nymphaea were all single grains,and the morphology was nearly spheroid or oblate spheroid.Among them,the pollen grains of N.gigantea were the largest,volume index was 30.3,and the pollen grains of N.lotus were the smallest,volume index was 19.2.(2)There were many types of patterns in water lily pollen,including checkered shape,small granular,nodular,small cylindrical,long strip.(3)According to the cluster analysis,the 18 species or cultivars of Nymphaea were divided into four subgenera,among which the Nymphaea and Brachyceras were most closely related.(4)The pollen germination rate of N.‘Peter Slocum’was more than 95%.It was believed that the pollen morphological characteristics of Nymphaea,especially the type of pollen germination gully and the patterns,could be used as the key evidence for the classification of Nymphaea species,the relationship between subgenera and species,and the law of Nymphaea.