Study On The Regulation Of Growth Quality Of Tomato Seedlings By Different LED Light Quality Nighttime Light Filling

In this study,tomato seedling was chosen as the test material.Treatments by six light qualities white light(W),red light(R),blue light(B)and combination of red and blue proportioning light(2R/8B,5R/5B,8R/2B)were used to light tomato seedling for 4h in the night,and no light was taken as contrast(CK)to study the most suitable tomato seedlings light quality,the objective of this study was to evaluate tomato seedlings growth,photosynthesis responses,nutrient absorption and cold resistance to different LEDs in night time.The conclusions of this test were as follows:1.Studying the effects of different LED light quality night-time lighting on the growth and development of tomato seedlings.This study showed,that each light treatment could promote the growth and development of tomato seedlings compared with CK,in which that red light R treatment was most beneficial to the increase of leaf area of tomato seedlings;blue light B promoted the accumulation of tomato seedling biomass significantly;The complex light(2R/8B,5R/5B,8R/2B)treatment were more beneficial to the root development of the tomato seedlings;At the same time,the 8R/2B treatment got the largest stem diameter,biomass and seedling index,and could prevent the seedlings moderate growth.It could also promote flowering earlier in the last time of seedlings growth effectively.2.Studying the effects of different LED light quality night-time lighting on photosynthetic characteristics of tomato seedlings.Studies showed that the content of chlorophyll a and chlorophyll(a+b)were the highest under the treatment of red and blue 8R/2B,while the content of chlorophyll b and carotenoid was highest in the treatment of white light W;the Φ PSII,qP and ETR are higher under the treatment of red and blue composite light 8R/2B and red light R,but the NPQ was lower.As while,the net photosynthetic rate,transpiration rate,intercellular carbon dioxide concentration and stomatal conductance of the seedlings treated with red and blue light 8R/2B were the highest.All in all,it showed that red and blue light 8R/2B was the most beneficial to improve the photosynthesis intensity of tomato seedlings.3.Studying the effects of different light quality night-time light supplement on nutrient uptake of tomato seedlings.Compared with the control CK,each supplemental light treatment could promote the nutrient accumulation of the seedlings.The red and blue composite light 2R/8B and blue light B treatment could simultaneously promote the N content in the stem and leaf of the seedling;red and blue light 5R/5B was the most beneficial to increase the total P accumulation of seedlings;while the red and blue light 8R/2B treatment has the highest total K and Mg content in the leaves and roots;meanwhile,the red and blue light 8R/2B treatments under the seedlings N,K The accumulation of Mg,Ca and B was the highest.All in all,the red and blue light 8R/2B as the supplemental light quality was the most beneficial to the nutrient absorption and utilization of tomato seedlings.4.The effects of different light quality on night-time lighting supplement on cold tolerance of tomato seedlings.During low temperature stress,compared with the control CK,the electrolyte permeability and MDA content of the tomato seedlings increased by the light-filling treatment,and the electrolyte permeability of the red-blue 8R/2B and blue-light B seedlings were smaller,and the content of MDA was lower;SOD,CAT and POD were all belong to enzymatic defense systems,and red-blue light(2R/8B,5R/5B,8R/2B)maintained higher level of SOD,CAT and POD during low temperature stress.As;while,the red-blue 8R/2B treament activity was the highest,indicated that the red-blue 8R/2B seedlings had the strongest ability to resist low temperature stress.5.The effects of various light-filling treatments on the growth quality of tomato seedlings were evaluated by fuzzy membership function method.The results showed that the red-blue 8R/2B as a supplemental light had a comprehensive effect on the growth of tomato seedlings and could be used as night-time lighting to tomato seedlings.