Effects of light emitting diode(LED)with different red/blue quality ratios on the growth of Dendrobium officinale plantlets in vitro

【Objective】 The effects of LED with different red/blue quality ratios on the growth of Dendrobium officinale plantlets in vitro were studied.【Method】 The Dendrobium officinale plantlets in vitro were cultured under LED with five different ratios(100%R(red),100%B(blue),80%R+20%B,70%R+30%B,50%R+50%B),and PGFL was used as control.After 90 days,the effects of different treatments on morphology,chlorophyll content,soluble sugar content,soluble protein content,and root activity of Dendrobium officinale plantlets in vitro were examined.【Result】 The plant height of Dendrobium officinale plantlets in vitro reached maximum under 100%R.The leaf number and root length reached maximum under 80%R+20%B.The root number reached maximum under 70%R+30%B.The dry and fresh weight,chl a content,chl b content,chl a+b content,soluble sugar content,and root activity all reached maximum under 50%R+50%B,and the soluble protein content reached maximum under 100%B.【Conclusion】 The LED with red/blue ratio of 1∶1 had the best effects on growth,synthesize chlorophyll,accumulate dry matter and sugar of Dendrobium officinale plantlets in vitro.