Preliminary Studies On Biological Characteristics Of Seeds And Cutting Propagation Of Plumbago Auriculata

Plumbago auriculata is indigenous to South Africa and falls into plumbaginaceae. Plumbagozeylanica also named as Plumbago auriculata Lam, is perennial shrub. Plumbago auriculata has a high ornamental value due to its variety of colors and blooming period. However, the studies on Plumbago auriculata now mainly focus on its chemical composition and pharmacological value, and little on biological characteristics, propagation speed and landscape application. In order to promote the application of plumbago auriculata, this assay carries out a systematic analysis on plumbago auriculata in terms of its phenological period observation, seed biology characteristics and cuttage propagation characteristics. The main research findings are as follows:(1) Plumbago auriculata is in good condition in the process of growing and blossom in Chengdu, and it is perennial plant that can grow out of the surface of land to live through the winter. It remains green throughout the year with a blooming period of5to10months and full blooming period of6to9months. The blooming period can be postponed for1to2weeks by top-pinching. Annual plumbago auriculata can come into flower within one year. It normally takes3months from seeding to first flower.(2) The seed of plumbago auriculata is large size seed. A thousand seeds weighs8.84g and there are113seeds per gram. The seeds have high vitality and rate of germination that they can be normally stored. The best temperature of germination is25℃and it would be better to soak them for10hours before seeding.(3) As for the hard wood cutting rooting rate, rooting number, length of root, vitality of root, the best treatment combination is IAA500mg/L+IBA500mg/L+NAA1000mg/L. The best soaking period is30minutes for the hard wood cutting in NAA100mg/L. If soaking base for30s with1000mg/L NAA, the best substrates are vermiculite and river sand (1:1) and the second best is garden soil. The best time for hard wood cuttage of plumbago auriculata is early March.Plumbago auriculata is popularly applied in Chengdu. However, because of its low seed setting rate, its garden value is in urgent need of exploration and deeper analysis is needed on its biology and propagation characteristics.