Effects of different light qualities on morphological and photosynthetic physiological parameters of soybean seedlings

In this study,three treatments of white light( CK),red /blue ratio = 0. 8,and red /far-red ratio= 0. 6 were set for simulating effects of different light qualities on the physiology and photosynthetic characteristics of soybean seedlings in maize /soybean relay intercropping conditions. Gongxuan 1 and Guixia 3 of soybean varieties were chosen as material. The morphology and photosynthetic physiological parameters of soybean seedlings under different light quality were analyzed. The results showed that soybean seedlings height were decreased and increased in red / blue treatment and red / far-red treatment compared with CK,respectively. And the opposite result was observed in stem diameter. Root length,above ground biomass,below ground biomass and shoot ratio of soybean seedlings in the red / far-red treatment were decreased significantly compared with the white and red / blue treatment( P 0. 01),but there was no difference of these paraments in white and red / blue treatment. The values of leaf area and photosynthetic pigment concentration in red / far red treatment appeared minimum and maximum respectively. In addition,The maximum values of net photosynthetic rates( Pn),stomatal conductance( Gs) and actual photochemical quantum yield of PSII( ΦPS Ⅱ) of two soybean varieties appeared in the blue / red treatment.However,there were no obvious regulation of intercellular CO2concentration( Ci),transpiration rate( Tr),PS Ⅱphotochemical transformation efficiency( Fv / Fm),PS Ⅱ potential activity( Fv /Fo) among different treatments.