观赏桃品种花粉形态与进化初步研究

Preliminary study on pollen morphology and evolution of Amygdalus persica L.

为了解我国北方地区常用的观赏桃品种间的亲缘关系,利用扫描电镜对22个品种的花粉进行了微观观察。结果表明:观赏桃的花粉均为大型花粉,均具有三孔沟。外观形状有超长球形和长球形2种,仅二色桃花粉粒椭圆形接近圆形。品种间的外观形态、条纹宽度变化差异均较小,而纹孔密度变化较大,外壁纹饰差别也较大。经聚类分析,帚型、寿星型品种分别聚在一组内,直枝型和垂枝型品种较分散。品种间的花粉粒外壁纹饰可分为条纹状穿孔纹饰、穿孔条纹状纹饰、条纹状纹饰3种类型。每个品种群内都有进化程度不同的品种存在,垂枝类型进化程度最高,其次为寿星型类型,直枝型类型品种进化程度有高有低。因此,不同观赏桃品种的花粉形态反映了一些新的亲缘关系,对观赏桃的杂交育种有指导意义。

In order to understand the genetic relationships among commonly used ornamental peach varieties in northern China,scanning electron microscopy was used to observe the pollen of 22 collected varieties.The results show that the pollen of ornamental peaches is large and has three pore grooves.There are two types of appearance shapes:super long spherical and long spherical,with only the‘two color’peach blossom powder particles being elliptical and close to circular.The differences in appearance morphology and stripe width between varieties are relatively small,while the variation in grain density is significant,and the differences in outer wall decoration are also significant.Through cluster analysis,the broom type and longevity star type varieties were clustered in a group,while the straight branch type and vertical branch type varieties were more dispersed.The pollen grain outer wall decoration among varieties can be divided into three types:striped perforation decoration,perforation stripe decoration,and stripe decoration.Within each variety group,there are varieties with varying degrees of evolution,with the highest degree of evolution being the hanging branch type,followed by the longevity type,and the varying degrees of evolution being the straight branch type.Therefore,the pollen morphology of different ornamental peach varieties reflects some new genetic relationships,which has guiding significance for hybrid breeding of ornamental peaches.