Regeneration of Laurocerasus hypotricha (Rehd.) T.T. Yu & L.T. Lu

One of the key challenges to introduce new woody plants is their difficulty of regeneration. Laurocerasus hypotricha (Rehd.) T.T. Yu & L.T. Lu (hairy cherrylaurel) is an evergreen tree with dense, lustrous foliage, loaded fragrant white flowers and smooth, reddish brown trunk. It has the great potential as an ornamental plant in various landscapes, especially urban conditions. To produce this plant commercially, seed germination, cutting propagation and tissue culture had been investigated. Seeds were collected and prepared for directly sowing and storing in room temperatures and moisture sand. All seeds were germinated under sand, loess and their mixes in outdoor conditions. Germination rates ranged from 50 to 67.4% and no significant difference was observed among the treatments. Cuttings had been collected in spring, summer and autumn, treated with 1000, 3000, and 8000 mg·L^-1 of IBA and NAA and rooted in media of perlite, sand, and mix of sand and loess. Timing had significantly effect on rooting of hairy cherrylaurel and less than 10% of rooting rates were obtained from spring softwood and summer semi-hardwood cuttings. Hardwood cuttings collected in autumn had 75% of rooting percentage and better quality of root system. The rooting hormone of 1000 or 3000 mg·L^-1 KIBA and perlite media should be applied. Young stems containing one axillary bud were disinfested and established on MS media. The sprouted shoots were cultured on MS media supplemented with 6-benzylaminopurine (BA) at 0.5 or 1.0 mg·L^-1 and/or 1-naphthaleneacetic acid (NAA) at 0.01, 0.05 or 0.2 mg·L^-1. BA and NAA did not significantly increase the number of shoots, but showed lower percentage of multiplication after 5 weeks with MS media supplemented with BA 1.0 mg·L^-1 and NAA 0.1 mg·L^-1. To induce rooting, shoots were subcultured on MS or ½ strength MS medium containing either NAA at 1 mg·L^-1 or indole-3-acetic acid (IAA) at 0.1 or 0.5 mg·L^-1.  Roots produced after 3 weeks and the highest rooting rate of 33.0% was obtained under ½ MS supplemented with NAA 1.0 mg·L^-1. Hairy cherrylaurel could be regenerated from seeds, stem cuttings, and tissue culture. Further studies should focus on increasing its reproduction rate.