Observation on Morphology and Histology of Angelica dahurica (Fisch.ex Hoffm.)Benth.et Hook.f.var. formosana (Boiss.)Shan et Yuan in the Process of in Vitro Cultivation and Polyploid Induction Studies on Polyploid Induction in Anthurium andraeanum Using Oryzalin,Trifluralin and Colchicine Induction and Identification of Tetraploids in Eucommia ulmoides Oliv. Studies on Polyploid Induction in Anthurium andraeanum Using Oryzalin,Trifluralin and Colchicine POLYPLOID INDUCTION OF Populus HYBRID THROUGH ZYGOTIC CHROMOSOME DOUBLING WITH HIGH-TEMPERATURE TREATMENT Study on induction of polyploidy in Salvia bowleyana by colchicine treatment Effects of Different Mutagenic Treatments on the Polyploid Induction of Miscanthus sinensis