Plant Regeneration And Callus Induction Of Camellia Oleifera

Using young stem segments with axillary buds as initial explants, the regeneration system of Camellia oleifera was established in this paper based upon the researches of axillary buds induction, shoots proliferation, strengthening and rooting. Researches were also conducted on the optimum hormone combination for calli induction from leaves, petioles and stem segments explants, on calli differentiation, and on browning inhabitation in calli induction from leaves as well. Main results were as follows:(1) Sterilization of explants:The young branches were collected from March to May as explants. In the experiment of axillary buds initiation, an initiation rate of 64.0%could be reached by sterilizing the stem segments with 0.1%HgCl2 for 8 minutes. In the experiments of calli induction, good induction rates of 73.6%,82.6% and 67.3% could be reached from leaves, petioles and stem segments respectively by sterilizing them with 2% NaClO for 21 minutes,21 minutes and 24minutes in respective.(2) Primary culture of stem segments with axillary buds:Good initiate culture medium was MS supplemented with 0.5 mg/L TDZ and 0.5 mg/L NAA. The initiate rate could reach 64.5%, and the average length of shoots could reach 1.6cm.(3) Shoots proliferation: A proliferation coefficient of 2.55 and a ratio of valid shoots of 0.74 could be obtained by cultured the shoots in MS supplemented with 3.0 mg/L 6-BA and 0.05 mg/L NAA.(4) Shoots strengthening and rooting:Different concentration of active carbon (Ac) designed in this experiment did not obviously promote shoots growing.1/2MS supplemented with 2.0 mg/L NAA and 20 g/L sugar could induce shoots to root and grow into complete plantlets.(5) Calli induction from explants:An induction rate of 74.5% could be obtained for calli induction from leaves in an optimum medium of MS supplemented with 2.0 mg/L 6-BA and 0.5 mg/L 2,4-D. The calli induction rate from petioles could reach 77.8% in the optimum medium of MS supplemented with 2.0 mg/L 6-BA and 2.0 mg/L 2,4-D. And that from stem segments could reach 67.8% in MS containing 4.0 mg/L 6-BA and 2.0 mg/L 2,4-D. Browning of calli induced from leaves could be restrained effectively after 7 days low-temperature pretreatment. (6) Calli proliferation and differentiation: Calli could successfully proliferate in proliferation medium of MS supplemented with 2.0 mg/L 6-BA and 0.2mg/L NAA, and some roots could be seen differentiated from calli in this medium. The differentiation medium needs to be researched in the future.