Study On The Influences Of Plant Growth Regulators On Dendrobium Nobile Micro-Propagation

Dendrobium nobile is species of defoliation, the natural florescences is February to April. Dendrobiums are important ornamentals, which are famous for their beautiful and attractive flowers and long florescences. So it is great potential for study on Dendrobium nobile.A cultivar of Dendrobium nobile Thong-In was used in this study. The induction of PLBs, shoot and root affected by several factors including explant types, plant growth regulators etc. A rapid and efficient regeneration system was established. The bud was found to be the best explant in terms of regeneration ability in the tested five types of explants. The best media for inducing PLBs or shoot and root developed. The primary results were summarized as follows:1. In this research, 1～3mm stem tip of Dendrobium nobile and 1/2MS are used as explant cultured in vitro and basic culture medium, respectively. Buds Sprouting and multiplication is induced by adjusting different level of plant hormones. research shows:(1)The medium of inducing: 1/2MS+6-BA0.5mg/L+NAA0.5mg/L +coconut milk200ml/L+cane sugar30g/L+active carbon3g/L+agar 5g/L, buds of explants sprouted early and grew fast in this medium; (2) in the stage of subculture and shoot multiplications, the best medium: 1/2MS+6-BA0.5 mg/L+NAA2.0mg/L+coconutmilk200ml/L+canesugarl5g/L+active carbon3g/L+ agar5g/L; (3) the medium for rooting: 1/2MS+NAA0.1mg/L+cane sugar15g/L+ active carbon 3g/L+agar5g/L, each stem node may grew four roots and better result appears in courage of culture.2. In the course of inducing PLBs of Dendrobium nobile, stem tip of Dendrobium nobile and 1/2MS are used as explant cultured in vitro and basic culture medium, respectively. PLBs and multiplication is induced by adjusting different level of plant hormones.The research shows: (1)The medium of inducing PLBs: 1/2MS+6-BA0.25mg/L+NAA5.0mg/L+2,4-D0.4mg/L+coconut-milk200ml/L+cane sugar 30g/L+active carbon 3g/L+agar 5g/L,buds of explants sprouted early and grew fast in this medium; (2) in the stage of PLBs multiplications: the best result is obtained in 1/2MS+ KT0.05mg/L+NAA2.0mg/L+coconut milk 200ml/L+ cane sugar30g/L+active carbon3g/L+agar5g/L; (3)The medium of differentiation PLBs:1/2MS+NAA0.2mg/L+BA0.5mg/L+coconut milk 200ml/L+ active carbon 2g/L+ cane sugar 30g/L+ agar 5g/L;The green and choiceness PLBs are induced triumphantly. (4)The medium for rooting: 1/2MS+NAA0.1 mg/L+cane sugar 15g/L+ active carbon3g/L+agar5g/L, each stem node may grew four roots and better result appears in courage of culture.