The Establishment of Clone System of Platanus acerifolia(Ait.)Willd

To dissolve the problem of falling seeds of Platanaceae,a new regeneration system was established by using the seeds of a mutant Platanus acerifolia(Ait.)Willd as explants.The results showed that the seeds were treated for 40 s with 70% alcohol and 40 min with 0.1% mercuric chloride(HgCl2)was the best distilled method on the premise that the germination of seeds was not influenced.MS+6-BA 6-7 mg/L+NAA 0.2-0.3 mg/L was the most suitable medium for callus induction and differentiation of the cotyledon explants;MS+6-BA 0.3 mg/L+NAA 0.01 mg/L was the most suitable medium of the multi-shoots induction.Adding suitable amount of GA₃ could obviously promote the growth of multi-shoots.2.5% sucrose concentration and 2/3 MS was the most suitable concentration to avoid vitrification of plantlets.The most suitable rooting medium was 1/2 MS+NAA 0.5 mg/L+6-BA 0.1 mg/L.In order to solve the problem of pollution that aroused by the floss of young shoots and leaves explants,one-step regeneration system of Platanus acerifolia(Ait.)Willd was established by using leaves of tube plantlets as explants.The suitable medium(MS+6-BA 1.5-2.0 mg/L+IBA 0.5 mg/L+NAA 0.5 mg/L)was selected from different regulator combinations.Compared with the method of using cotyledon as explants,the one-step regeneration system had many obvious advantages.It laid the foundation for genetic and transge-nic manipulation of Platanaceae and also provided reference for genetic improvement of other plants,especially for elite trees.