Research In Culitivar Resource And Characteristics Of Variegated Chimera In Hosta

Hostas,as important landscape plants used for ground cover in the forest, have been planted in Europe and America countries for many years. Being ornamental value of flowers and foliages, broadly adaptable and shade tolerance, hostas have been broadly applied for landscape use in China in recent years. Based on systemically analysis of Hosta germ plasm resource, cultivar resource, and the status of multipropagation technology and chimera researches, some investigation and experiments have been done in this article, including tissue culture, chimera characteristics, production and applying status of hostas in China. The result were summarized as follows:1. The process of initial culture showed quite difference in various hostas. H. ventricosa and H. 'So Sweet' were easier, while H. 'Frances Williams' and H.'Gold Standard' were difficult. Using shoot tip (peak bud) as explant was proved the effective method for improving survival ratio when hostas would defoliate or have defoliated in autumn or winter rather than in summer.2. The better way is by the axillary bud to multipropagate variegated Hosta cultivars. Higher value of BA/NAA improved the initition of axillary bud, but as the result, the variegated parts were lost.3. Shading levels effected on the growth of cultivated plantlet from adventitious buds in plastic house. Lower shading level could increase the root development including root number, fresh weight and dry weight.4. Analysis of chlorophyll in different parts of variegated leaf from H. 'So Sweet' showed that the content of chlorophyll a (0.634mg/gfw), the content of general chlorophyll (0.807 mg/gfw) and chlorophyll a/b (11.785) in yellow part were all the lowest in three parts and H. ventricosa, while the content of chlorophyll b was the highest.5. In green part of leaf from H. 'So Sweet' , there was a estrase isozymograms (Rf0.55) more than others.6. From green part, transition color part to yellow part of variegated leaf from H. 'So Sweet' , the changing ultrastructure of chloroplasts is roundness from ellipse,granum-thylakoid swelling, vesicle bringing and osmiophile globule adding.1. H. ventricosa and more than three Hosta cultivars, were applied in gardens and virescences in Hangzhou, but showed worse in hot summer. It resulted in no correctly considering the factors, such as temperature, shading and air humidity during plant designing.8. Some suggestions were provided for hostas production and some Hosta horticultural cultivars were recommended for landscape use.