河南12种乡土荷花的花粉形态特征及聚类分析

Analyses of pollen morphology and cluster of the twelve indigenous Nelumbo nucifera species in Henan

调查了河南省乡土荷花品种的主要分布地区,采集12个品种的花粉,利用扫描电镜进行观察和测量,并进行了聚类分析.结果表明,荷花花粉形状为近球形,大小为极轴长34.2~55.3μm,赤道轴长39.5~56.7μm;具3条萌发沟,无沟膜,辐射对称,均等分布;3条沟在极面不交会,有沟界极区.外壁纹饰为脑纹状或脑纹皱波状.花粉种间差异主要表现在大小、形状、外壁纹饰和萌发沟性状的细微变化方面.经聚类分析在遗传距离5.01处,可将12个乡土品种分为2大类,在遗传距离3.56处分为4小组.组别与乡土荷花品种的地理分布及远近有一定的关系.

Field investigation to the primary distribution region of indigenous Nelumbo nucifera species in Henan Province was carried out.Pollen morphology of 12 different Nelumbo nucifera species were observed and measured in SEM.Observational study and cluster analysis on the results showed：The pollen grains were subspheroidal in shape.The polar axis was in the range of 34.2～55.3 μm,and the equatorial axis was 39.5～56.7 μm.The pollen grains had three germinal furrows without colpus membrane,which were actinomorphic and equal distribution.The three furrows had sulci limitantes,but didn＇t intersect on the polar.The pollen exine sculptures were striatum and rugulate-ripple.The main difference among the pollen grains of 12 species was embodied in the subtle change of size,shape,sexine sculpture and germinal furrow characters.The observed Nelumbo nucifera species can be divided into two main categories when the coefficient of genetic similarity was 5.01,and four groups when it being 3.56.The groups had a certain relationship with the distribution distance of indigenous Nelumbo nucifera species.