Pyracantha coccinea is a thorny evergreen shrub native to southeast Europe to southeast Asia. It is a popular ornamental plant because of its showy bright red fruits and small white flowers. However, in vitro vegetative propagation of P. coccinea has not been studied. Nodal segments with one or two axillary buds (1 to 1.5 cm in length) were cut and disinfected in a solution of 0.1% (v/v) mercuric chloride (HgCl2) for 5 minutes, and proliferated on Murashige and Skoog (MS) basal medium supplemented with various concentrations 6-benzylaminopurine (6-BA). After 4 weeks, newly formed shoots were transferred to proliferation and rooting media containing various concentrations of indole-3-butyric acid (IBA). Establishment of axillary buds was significantly better with an establishing rate of 67% on basal MS medium augmented with 6.6 µm 6-BA. The best medium for proliferation of shoots was three-fourth basal MS supplemented with 1.5 µm IBA, with a proliferation rate of 3.4 axillary bud. The optimum rooting medium was one-fourth MS basal medium containing 93 µm IBA. Rooting of shoots was as much as 77%. Rooted plantlets were transferred to pots containing vermiculite:perlite:peat (6:1:2) and acclimatized to ambient greenhouse conditions with a 95% survival rate. This protocol can be used for in vitro propagation of P. coccinea.
Chao Dong, Xue Li, Yue Xi, and Zong-Ming Cheng
Yiguang Wang, Chao Zhang, Bin Dong, Yaohui Huang, Zhiyi Bao, and Hongbo Zhao
Chinese flame tree (Koelreuteria bipinnata var. integrifoliola), a common ornamental tree in southern China, exhibits a variety of fruit colors among individual plants within the same cultivated field. In this study, 44 plants with different fruit colors were selected to investigate the impact of pigment composition on the coloration of fruit peels. The plants were divided into three groups based on the color phenotype of the fruit peel: red, pink, and green. The values of lightness (L*) were negatively correlated with redness (a*) and positively correlated with yellowness (b*). The correlations of chroma (C*) with the other color parameters differed among the three groups. In the pooled pink and red groups, C* was negatively correlated with both L* and b* and positively correlated with a*, whereas the opposite relationships were found in the green group. According to the pigment analysis, anthocyanins, chlorophylls, and carotenoids were detected in the fruit peels. Anthocyanins were found to be the main pigment responsible for the differences in fruit color among the various groups. The highest anthocyanin content of fruit peel was found in the red group, followed by the pink group; the lowest anthocyanin levels appeared in the green group. The major anthocyanin component in the fruit peels was identified as cyanidin 3-O-rutinoside. By classifying fruit peel color and determining pigment composition, this study provides a theoretical basis for further researching genetic control and regulation of anthocyanin biosynthesis genes on pigment accumulation and peel coloration of chinese flame tree.