二月兰形态性状的变异分析

二月兰(Orychophragmus violaceus)是集食用、保健、饲用和观赏于一身的优良地被植物。其遗传背景单一、生长周期短,是发展模式植物的优良材料。为了开发其育种价值,我们对二月兰的形态变异式样进行了初步分析。共选取了北京和南京地区的7个居群的34个表型性状进行观测。通过计算分析发现:株高、茎和花序分枝等性状受环境影响较大,因而其分类价值不大;叶形、毛被、叶缘锯齿等性状的变异在居群内是连续的,所以也不是可靠的分类性状;而花部性状的一些变异,包括花瓣的颜色、大小、形态,基本不受环境影响,且这些变异在居群内是不连续的,所以其分类价值相对较高。对17个数值性状的方差分析和多重比较结果表明,在同一年度内,大部分性状在不同地区间差异不显著,在居群间差异极显著;而在不同年度内,居群间差异不显著。最后,对7个居群和30个表型性状进行了数量分类:Q分析表明北京颐和园、南京紫金山山顶公园和南京中山植物园居群比较相似,而北京圆明园、北京海淀区后八家苗圃、南京情侣园和北京天坛公园居群较相似。R分析揭示了二月兰花部、叶部、反映植株毛被和颜色以及表现植株生长量的性状间均具有一定的相关性。这些研究可为种下等级的划分和进一步的遗传研究以及品种培育提供一定的参数资料。

Variation of morphological characteristics of Orychophragmus violaceus

Orychophragmus violaceus is widely used for forage, health care and gardening. In order to develop its value,we studied the patterns of its morphological variation. We sampled seven populations from Beijing and Nanjing and measured 34 morphological characters. The results showed that stem height,stem and inflorescent ramification are multiform in different habitats, and therefore have little taxonomic value. The variations of leaf shape, leaf margin and leaf hair are continuous within populations, indicating that they are unreliable for taxonomy. The variations of flowers, including color, size and form of petal are uncontinuous and vary within populations, showing high taxonomic value. The analysis of variation and multiple comparisons of the 17 numerical characters indicated that, in the same year, most of these characters are significantly different among populations. In contrast, these differences are inconspicuous between localities. In different years, differences are inconspicuous among populations. Finally, we analysed seven populations and 30 characters using numerical taxonomic methods. Q cluster analysis found that the three populations from the Summer Palace, Zijin Mountain Park and Zhongshan Botanical Garden of Nanjing were grouped together and as were the other four populations. R cluster analysis showed that characters of flower, leaf, and those involving the hair and color of plants were grouped together, respectively, and so were characters involving growth volume.