Effects Of Light Emitting Diodes On The Growth And Development,Yield And Quality Of Eggplant

Eggplant(Solanum melongena L.) cultivation area expands year by year in our country, and it is one of the most important vegetables for sale in domestic and export markets. Previous studies found that red film was contributed to heathy seedling cultivation and the growth and development of eggplant under the same light intensity. Because the spectral composition of different color films are complicated, it is difficult to study the concrete regulation mechanism further. LED(Light Emitting Diode) has less monochrne, fever, monorner samall size, long life, no pollution and many other advantages. At the same time, LED can provide pure light qualities to increase the reliability of the study. ?Brigitte? eggplant was used as experimental material. Red light, blue light, red+blue light and white light(as control) generated by LED were applied. The effects of the different light qualities on the growth, yield and fruit quality of eggplant were studied in order to provide theoretical and technical support for the heathy seedlings cultivation and the development of light quality environmental regulation for the protected cultivation and improvement of fruit quality. The results showed that:1. The stem diameter, leaf area, dry weight, root/shoot, seeding index, leaf thickness, palisade tissue thickness and root activity were the highest under red+blue light; Compared with the control, the stem diameter, dry weight, root/shoot, seeding index, leaf thickness and root activity were lower under red or blue light, and those were lowest under red light. In the fruit setting period of eggplant, the stem diameter and leaf area were higher under red light; the root dry weight and root activity were the highest under blue light; the total plant dry weight and aboveground dry weight were the largest under control.2. Light qualities could influence the nitrogen metabolism of plant, and adjust the carbohydrate and protein metabolism. Under blue light, the content of total nitrogen, soluble protein and free amino acid were significantly higher 55.2%, 26.8% and 5.5% than control respectively. The soluble sugar was the highest under the red+blue light, followed by red light.3. Under red+blue light, the content of photosynthetic pigment, Pn and ΦPSII were the highest; the chlorophyll a/b, Fv/Fm and q P were the highest under blue light; Those under red light were lowest. In the fruit setting period of eggplant, the photosynthetic pigment content was highest; The Pn, Tr, Gs, Fv/Fm, ΦPSII and q P were highest under red+blue light but lowest under red light.4. Under blue LED, the soluble protein, free amino acids contents of eggplant pulps and the anthocyanin content of eggplant peels were highest, but flavonoid and phenolic contents of pulps and the yield were lower than other treatments. Under red LED, the eggplant peels flavonoid was remarkably increased, but vitamin C(VC) and soluble protein contents were considerably decreased. Under red+blue LED, the soluble sugar of pulps and phenolic, red pigment, yellow pigment contents, total antioxidant capacity(TAC) of peels and the yield were significantly higher than other treatments. While VC, flavonoid and phenolic contents and TAC of eggplant pulps were the highest under white LED.