金槐和米槐主流品种花粉形态研究

Observation on pollen morphology of main varieties of Sophora japonica ‘Jinhuai' and S. japonica ‘Mihuai'

关键词:  金槐, 米槐, 花粉, 扫描电镜, 亲缘关系

Key words:  Sophora japonica ‘Jinhuai', S. japonica ‘Mihuai', pollen, SEM, relative relationships

摘要:

该研究以6个金槐品种和2个米槐品种的花粉为材料,采用美国卡尔蔡司EVO18扫描电镜对其极面、赤道面、外壁纹饰等形态特征进行了观察,并对金槐、米槐品种间的亲缘关系进行了分析。结果表明:(1)金槐和米槐花粉的共有特征有极面观为三裂圆形,极面光滑; 具3孔沟,沟较窄且达两极; 沟缘中部外凸,具颗粒状突起; 沟在极面上没有交会,形成宽大的沟界极区。(2)金槐的花粉粒为长球形,金槐J6的极轴最长,金槐J2的极轴最短,极轴长/赤道轴长表现的规律与极轴长相一致; 网眼直径最大的是金槐J2,最小的是金槐J5; 网眼密度最大的是金槐J6,最小的是金槐J2。(3)米槐的花粉粒为近圆球形,极轴长和极轴长/赤道轴长明显小于金槐,但其赤道轴长大于金槐; 双季米槐的赤道轴长、极轴长、极轴长/赤道轴长、网眼密度都小于单季米槐。(4)8个品种可分为3组,金槐J4、金槐J1和金槐J6 3个品种亲缘关系较近,金槐J5、金槐J3和金槐J2 3个品种亲缘关系较近,单季米槐和双季米槐2个品种亲缘关系较近。花粉形态是鉴别金槐和米槐两大类品种的重要根据,并可为进一步的品种划分提供重要依据。

Abstract:

The pollen morphology of six Sophora japonica ‘Jinhuai' and two S. japonica ‘Mihuai' varieties were observed by scanning electron microscopy(SEM), and the relationship was analyzed. The results were as follows:(1)The common characteristics of the pollen of Sophora japonica ‘Jinhuai' and S. japonica ‘Mihuai' included that the polar surface was three-lobed round and the polar surface was smooth; three narrow hole groove reached two poles; middle part of the groove edge was convex and granular protrusions; the groove did not meet on the polar surface, forming a wide trench boundary.(2)The pollen of S. japonica ‘Jinhuai' were nearly spherical, the polar axis of Jinhuai J6 was the longest, and that of Jinhuai J2 was the shortest, the law of polar axis/equator axis was consistent with polar axis. The diameter of the mesh of Jinhuai J2 was the largest, and that of Jinhuai J5 was the the smallest; Mesh density of Jinhuai J6 was the largest, and that of Jinhuai J2 was the smallest.(3)The pollen grains of S. japonica ‘Mihuai' were nearly spherical, and the polar axis/equator axis was significantly smaller than that of S. japonica ‘Jinhuai', but the equatorial axis was larger than that of S. japonica ‘Jinhuai'; the equatorial axis, polar axis, polar axis/equator axis and mesh density of S. japonica ‘Shuangjimihuai' were lower than those of S. japonica ‘Danjimihuai'.(4)The eight varieties could be divided into three groups, Jinhuai J4, Jinhuai J1 and Jinhuai J6 were closely related to each other, Jinhuai J5, Jinhuai J3 and Jinhuai J2 were closely related to each other, Shuangjimihuai and Danjimihuai were closely related to each other. It can be concluded that pollen morphology was an important character for identifying S. japonica ‘Jinhuai' and S. japonica ‘Mihuai', and it can be an important basis for further classification of varieties.