Regeneration Plantlet System For Weigela Florida Cv'Red-Prince'

Weigela florida cv. 'red-prince' is an important garden ornamental species introduced from America recently. At the present time it is propagated by cutting and separate plantlets. A few of researches about tissue culture of W. florida cv. 'red-prince' have been reported in the world. To establish regeneration plantlet system, this paper studied the aseptic shoots establishment, basal medium, plant growth regulators combination and concentration, inducing rooting as well as callus tissue induction and differentiation for W. florida cv. 'red-prince' in vitro. The results were as follows:(1) It is suitable to sampling explants from late of March to early of May. The original explants were surface-sterilized by agitating in a solution of 0.1%HgCl2 for 4～6 min, followed by wash two times in sterile distilled water, then agitated in 5%NaClO for 10 min, and finely rinsed three times with sterile distilled water.(2) Basal medium MS with high concentration of salt ions is more suitable for stem segment initial and proliferation culture than other low salt medium such as B5 ,WPM and 1/2MS. (3) Adding 2.5mg/l 6-BA to the medium in subculture improves the multiplication of shoot, but inhibits shoots to elongate. The effect is not significant on the multiplication of shoot by adding 2.5mg/l 6-BA with 0.05～0.1mg/l NAA to the medium, but it can improve shoots elongation greatly. Moreover shoots are strong and in full vigor. (4) The elongation of shoots was greatly promoted by GA31.0～2.0mg/l in medium. Adding GA30.5～1.0mg/l with 6-BA2.5mg/l to medium not only increased shoots number but also improved shoots length. The concentration of GA3 should not exceed 1.0mg/l, otherwise shoots will become slightness and thinner , and more air-roots.(5) The best proliferation medium was MS +6-BA2.0mg/l+NAA0.06mg/l + GA30.6mg/l, in which the average number of shoots can reach 5.1 and length 1.9cm . (6) The quality of the root system was excellent on WPM medium with NAA0.1mg/l, IBA0.05mg/l and sucrose20g/l. Rooting rate was more 90% .(7) The quality of callus is not different significantly by leaf back and stem slit upturned inoculated on callus inducing medium. The inducing rate and growth speed of callus were heightened by fifteen days-dark culture firstly, and then days-light culture.(8) In adjusted MS medium, different auxin and cytokinin combination and concentration proportion effect significantly on callus inducing and growth. The callus on mediun with NAA and 6-BA was tighten and fresh green. There were some adventitious roots induced on medium with NAA0.5mg/l and 6-BA1.0～2.0mg/l , while NAA0.5 mg/l and 6-BA3.0～4.0mg/l very few single bud could be induced . (9) There were not cluster shoots in all the course of callus induction, but a lot of adventitious roots and gassy roots. By observing callus cell gemmiform organ was not founded,but some adventitious roots characters.