新疆胡颓子属植物花部性状的变异及其分类学价值

新疆胡颓子属植物栽培历史久、变异丰富、种下变异类型多、分类较为困难,因此有必要进一步发掘该属落叶组植物的分类学特征,尤其是对相对保守的繁殖器官的性状进行筛选。该研究以形态较为稳定的繁殖器官为切入点,分析花部性状的变异特点,筛选稳定性状,以期为解决该属的分类难题提供依据。先采用定株采集和同花标记的方法,对比分析了柱头形态、花盘先端有毛无毛、花柱与雄蕊的长短比、花被裂片程度四个性状的稳定性。结果表明:花盘先端有毛无毛、花柱与雄蕊的长短比、花被裂片程度三个性状较稳定,可以作为分类依据;柱头形态在单花中表现稳定,但在单株中出现极大的变异,不具有分类价值;然后采取新疆南、北疆地区的胡颓子属落叶组的尖果沙枣、大果沙枣和沙枣这三种来验证花部性状的稳定性,证明了上述结论的正确性,同时也是对该属分类研究实践的应用。该结果可为胡颓子属的经典分类学和形态学研究以及植物的开发和利用等提供参考依据。

Floral traits variation and its taxonomic value of Elaeagnus in Xinjiang

Elaeagnus has been cultivated for a long time in Xinjiang. There are rich variations and many taxa about the species,and the taxonomy is difficult. In order to provide more evidence for solving the classification problem,a more stable form of reproductive organs as a starting point was to analyze the characteristics of floral traits variation,and select the stable traits. We analyzed the stability of stigma form, glabrous on apex of flower disc, length ratio of style to stamens, the proportion of perianth lobes to perianth fixed plant and labeled flowers. The result showed that three traits weree relatively stable: glabrous on apex of flower disc,length ratio of style to stamens,the proportion of perianth lobes to perianth, which could be used as a basis for distinguishing species; stigma form was stable in a single flower, but varied in single plant, which did not have a classification value. Finally,verification tests of floral traits proved the correctness of the above conclusions, but also was the classification of the genus practical application, providing the basis data for the study of classic reference taxonomy, morphology,the development and protection in Elaeagnus.