Variation of morphological characteristics of Orychophragmus violaceus

Abstract

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.