|
The effects of different light qualities generated by light emitting diodes (LED) on growth and physiological characteristics of cucumber seedlings were studied. Eight treatments were designed with red LED (R), blue LED (B) and the combination light of red and blue LED (R/B=9:1,8:2,7:3,6:4,5:5), compared to the treatment of white fluorescent light (CK). As the results showed that:1. The cucumber seedlings had bad growth status under only red and blue LED light. The healthy index and biomass under the combination light of red and blue LED were higher than single light.2. Under the combination light of red and blue, chlorophyll content, Fv/Fm,ΦPSⅡ, qP in cucumber seedling leaves were higher than single red, blue light treatment. Indicating that combination light had the potential activity of PSⅡand the original light higher energy conversion efficiency, photosynthetic electron transport rate faster, higher energy utilization efficiency.3. Red light was beneficial for elongation of root and stem and dry matter accumulation. Blue light was beneficial for seedlings stocky.4. Under blue light, the root length, root dry weight, rate of root/shoot, root activity of cucumber seedlings were least. These results showed that blue light was negative growth of root.5. The red light was beneficial for synthesis of soluble sugar and the blue light was beneficial for synthesis of soluble proteins.6. There were highest SOD、POD、CAT、APX activity under blue light, it was showed that blue light could enhance the activity of antioxidant enzymes.7. Under the combination light of R/B=7:3, the specific leaf weight, fresh weight and dry weight of seedling, net photosynthetic rate (Pn), chlorophyll content and healthy index were highest. The results showed that the light was suitable for the growth of cucumber seedlings.
|