Study On Technology About Tissue Culture And Rapid Propagation Of Pinus Elliottii×Pinus Caribaea

Pinus elliottii XPinus caribaea is the hybrid offspring of Pinus elliottii and Pinus caribaea. It is a favoured afforestation species in our country because of its many superb properties, such as fast growth,good adaptation and so on. In recent years, the afforestation area of Pinus elliottii XPinus caribaea is growing larger in Southern China. And because its low seed production and high cost of production, the problem of the supply of seeds and seedlings couldn't meed the need by afforestation is becoming more glaring with each passing day. So, it is of great value to propagate rapidly seedlings of Pinus elliottii XPinus caribaea by the means of tissue culture.This article research the direct organogenesis ;and plantlet regeneration of Pinus elliottii XPinus caribaea with the tender stems of the year as the explants.To the explants which carry more germ, there is a better result with the pretreatment of seriously scrubing before the treatment of 75% ethanol 10 seconds+0.1%HgCl2 6 minutes.After several contrast tests, it shows that selecting the stems from the nurseries of Dongmen Forest Farm which have tender needles in a leaf axil as explants were favourable to the axilly bud induction of Pinus elliottii XPinus caribaea . and only the axilly buds in the base and in the middle part of the stems are inducible.DCR medium was the better elementary medium for axillary buds differentiation of Pinus elliottii X Pinus caribaea. Axillary buds were induced in DCR medium supplemented with different levels of 6-BA and NAA. The better medium for Pinus elliottii X Pinus caribaea to induce axillary buds was DCR supplemented with 6-BA(lmg/L) and NAA(0.05-0.15mg/L) or DCR supplemented with 6-BA(2mg/L) and NAA(0.1 -0.2mg/L). In which the differentiation frequency was higher, At the same time the growth and development of the axillary buds were normal. DCR medium supplementedwith sucrose(40g/L)was relatively suitable to the differentiation of the axillary buds in Pinus elliottii XPinus caribaea,When successive transfer culture, the addition of NAA(0.1 mg/L) or AC (1.0 mg/L) to DCR medium or the DCR medium without hormone could efficiently promote axillary buds to elongate and grow. In the subsequent successive transfer culture(after the second successive transfer culture ), the explants must transfer to the medium whose salinity is higher, such as WPM . So that the axillary buds can grow and develop normally.The grown axillary buds can proliferate in original induced medium. The combination of DCR+6-BA2.0mg/L+ NAA0.2mg/Lwas relatively suitable to the proliferation of the axillary buds in Pinus elliottii XPinus caribaea. In which the differentiation frequency accounted for 62.5%. In this study, no medium was found to meet the requirement of the adventitious buds to grow up.Basal media composition, the kind and the concentration of auxin significantly influenced the rooting of the regenerated plantlets in Pinus elliottii XPinus caribaea. In the study about the rooting of the regenerated plantlets in Pinus elliottii XPinus caribaea, only the half DCR supplemented with NAA(a certain concentration) could induce adventive root to come into being. The half DCR medium supplemented with NAA(0.1mg/L) was suitable to the root induction of the regenerated plantlets in pinus elliottii XPinus caribaea, in which the frequency of induction was 50%.