Effect of the Status of Adventitious Buds In Vitro Cultured from Mature Embryo of Pinus tabulaeformis on Its Rooting Rapid Propagation and Regeneration System of Populus simonii×Populus nigra Induction of Adventitious Buds from Stems without Axillary Bud of Aristolochia debilis Sieb. et Zucc Effect of plant growth regulators on several characteristics during in vitro bud regeneration of Polygonatum cyrtonema Tissue Culture Technique for Rapid Propagation of Lippia triphylla