杜鹃花属植物种间可交配性及其特点

Crossability and its characteristics of Rhododendron

关键词:  杜鹃花属, 杂交亲和性, 可育性, 可交配性, 植物系统学

Key words:  Rhododendron, cross compatibility, fertility, crossability, plant systematics

摘要:

该研究以杜鹃花属5亚属3组17亚组38种和 共计91个可育组合及109个不育组合的杂交结果为依据, 通过杂交可育指标频度分析, 初步揭示该属植物种间可交配性的分布规律。结果表明:(1)根据育性等级频度的研究, 可得到种间可交配性排序结果,即亚属级:常绿杜鹃亚属内杂交>杜鹃亚属内杂交>常绿杜鹃亚属×杜鹃亚属>杜鹃亚属×映山红亚属>常绿杜鹃亚属×映山红亚属>常绿杜鹃亚属×羊踯躅亚属>常绿杜鹃亚属×马银花亚属>杜鹃亚属×羊踯躅亚属; 亚组级:银叶杜鹃亚组×同亚属的其他亚组>云锦杜鹃亚组内杂交>云锦杜鹃亚组×银叶杜鹃亚组>银叶杜鹃亚组×杜鹃亚属各组>三花杜鹃亚组内杂交>云锦杜鹃亚组×同亚属其他亚组>云锦杜鹃亚组×杜鹃亚属各组>常绿杜鹃亚属的其他亚组×杜鹃亚属各组。(2)种间可交配性与亲本间的亲缘关系及染色体倍性有明显的关联, 与分类系统中所反映的类群亲缘关系契合, 原始的杜鹃花属植物类群如常绿杜鹃亚属可能比较进化类群具有更广泛的可交配性。(3)坐果率、绿苗率、绿苗系数和单位可育种子数量及其等级频度能从不同的侧面反映杜鹃花属植物杂交可育性数量特征, 但也分别存在某些局限性, 建立综合评价方案和可育性等级频度指标十分重要。

Abstract:

The distribution rule of inter-specific crossability of the genus was studied, based on 91 fertile and 109 sterile cross combinations, involving 38 Rhododendron species which belong to five subgenera, three sections, seventeen subsections through hybridization fertile frequency analysis. The results were as follows:(1)According to the study on the frequency of fertility level, the results of specific hybridization between the groups could be sorted as on subgenus level: intra-subgen. Hymenanthes>intra-subgen. Rhododendron>subgen. Hymenanthes×subgen. Rhododendron>subgen. Rhododendron.×subgen. Tsutsusi >subgen. Hymenanthes×subgen. Tsutsusi>subgen. Hymenanthes×subgen. Pentanthera>subgen. Hymenanthes×subgen. Azaleastrum>subgen. Rhododendron×subgen. Pentanthera; on subsection level: subsect. Argyrophylla ×the other subsectiosns of the same subgenus>Intra-subsect. Fortunea>subsect. Fortunea× subsect. Argyrophylla>subsect. Argyrophylla×subsectiosns of subgen. Rhododendron >intra-subsect. Triflora>subsect. Fortunea×the other subsectiosns of the same subgenus>subsect. Fortunea×subsectiosns of subgen. Rhododendron >the other subsectiosns of subgen. Hymenanthes×subsectiosns of subgen. Rhododendron.(2)Inter-specific crossability was obviously relevant to the genetic relationship and chromosome ploidy of the parents and correspond to the relationship of plant systematic of Rhododendron, and the original group, such as subgen. Hymenanthes, had more extensive crossability than more advanced one.(3)Capsul setting rate, green seedling rate, green seedling coefficient, unit number of fertility seed and their class frequency reflected a fertile quantity characteristic of Rhododendron hybrid from different side, with some limitation. It is very important to set the system of comprehensive assessment and the index of fertile level frequency.