Effects of Different Light Emitting Diode Sources on Growth and Chlorophyll Fluorescence Parameters in Garlic Seedling

This paper studied on the effects of different light qualities on growth and chlorophyll fluorescence parameters of garlic(Allium sativum L.)seedling.Red light,blue light,red+blue(R+B)light generated by light-emitting diode were applied,and white light generated by fluorescent lamps was used as control.Effects of different light qualities on growth and chlorophyll fluorescence parameters of garlic seedling were significantly different.The height,diameter,length of pseudo stem and value of dry weight to fresh weight were the highest under red light,whereas contents of chorophyll(a+b)and carotenoid were the highest under white light treatment.The photosynthetic rate(Pn),transpiration rate(Tr)and stomatal conductance(Gs)were the biggest under red light,while intercellular CO2 concentration(Ci)was highest under white light.The fluorescence parameters were significantly affected by light quality.Values of the maximal photochemical efficiency of PSⅡ(Fv/Fm)and Fv/Fo were the highest under red+blue(R+B)light,quantum yield of PSⅡ(ΦPSⅡ)was the highest under white light,but there was no significant difference between white and red light.The Pn of garlic seedling were significantly increased under red light,thus the growth and dry matter were also significantly increased.