STUDY ON THE MICROPROPAGATION OF THE MINIATURE ROSE (Rosa Chinesis . Minima) AND THE MECHANISM OF ROOTING DURING THE TISSUE CULTURE

By summarizing the research about Miniature Rose (Rosa chinensis. Minima or Rosa roelletti), this study aimed to select optimum culture medium and conditions for Miniature Rose with several representative varieties in flower colour, especially focused on the techniques of the establishment of aseptic cultures, proliferation, strengthening and the rooting in vitro and ex vitro of the plantlet. Further more, this article discussed the mechanism of the rooting during the tissue culture. At last, the tissue culture system of Miniature Rose was established as follows: 1. Establishment of aseptic cultures: the explant (9.0?0.0mm in length/3.O?.Smm in diameter, 5.0mm above/under the node) was node segment with one axillary bud under the intact leaf from the flowering stem. After being disinfected with 75% alcohol and 0. 1% HgCJ2 , the explants were dipped in to lOOmg/L gentamicin solution for 30 mm to eliminate the germs in, then were inoculated in 100m1 vessels, each with 4? explants. The inducing medium was: MS+6桞A lmg/L+NAA 0. 1?. 2mg/L +KT O.5mg/L. After inoculation, 1600?000Lux light intensity, 16梙s light period and temperature in 200C was succeeded with treatment of 2梔ay darkness. 2. Proliferation and Strengthening: The regenerated bud was transferred to the medium of MS+6桞A3?mg/L+NAA 0. 1?. 2 mg/L +Sucrose 30?5g/L+agar 6?.5g/L. PH5.9, Th22XD, LI (Light intensity) 800?600 Lux, LP(Light Period>l6hs. The proliferation of Miniature Rose has the quantity effect Three buds as a transferring unit resulted in the highest proliferating rate. 3. Rooting in vitro: The strengthened plantlet (height of 20?5mm) was transferred to the rooting medium of l/2MS(the concentration of Ca2~ was increased to 1.5 times)+ NAA 0. 2mg/L (or NM 0. lmg/L +IBA 0. lmg/L) +Sucrose 20?5g/L+agar 7g/L+AC 0. 4g/L. after being transferred, the temperature was 220C in the first week, than decreased to l8~C. Tube was the best container for rooting. Other culturing conditions were the same as above. 4. Rooting ex vitro: Cultured 6? week, the plantlet (with the height of 20?5mm) was taken out from the vessel, after washed off the agar round the end, the plantlet was dipped into JBA solution(50g/L) for 5mm and then was inserted to the medium mixed of peat and sand(l :1, V/V), growing under natural light with T=22 慍 . 2ldays later, transferred the acclimated plant to the medium mixed of loam, peat and perlite (l:i:i,V/V/V), slowly developed to the natural condition. By comparing in vitro and ex vitro rooted plant, we found that different rooting method affects the plant growth and development. 2ldays after these two rooting treatments, the ex vitro root was white, longer, larger in quantity and diameter, larger proportion of vascular, which developed earlier and had better flexible, and had branch root while the in vitro root was dark, thinner, brittle and without branch root. Except for the variety of 憀ittle red? the growth of root (diameter and dry weight) and stem (height, diameter and dry weight) of the ex vitro rooted plant were larger than those of in vitro rooted plant. 5. Discussion of the mechanism of rooting during the tissue culture: By determining the endogenous substance periodically during the rooting of Miniature Rose tissue cultured course, it was found that the content of IAA in rhizogenic zone increased before the formation of primordium and decreased after formation. While iPAs and ZRs slightly decreased before...