The Effect Of Different LED Light Quality On The Growth And Quality Of Buckwheat Sprouts

Light quality is an important factor affecting plant morphogenesis,growth and development,photosynthesis,and material metabolism.The regulation of light quality is the key to the production of sprout vegetables.The use of light emitting diode(LED)light sources to regulate the light environment of sprout vegetables,promote their growth and development,and improve their nutritional quality is currently a new research hotspot in sprout vegetable facility planting.Buckwheat sprouts and vegetables can be cultivated and produced using soilless cultivation techniques,and are a new type of vegetable that combines advantages such as nutrition,health,and medicinal value.This article uses buckwheat(Fagopyrum esculentum Moench.)sprouts as experimental materials,and sets LED red light(Red,R)at 660 nm and LED blue light(Blue,B)at455nm.The light quality ratio is five different light quality treatments: red blue 5:1,red blue 3:1,red blue 1:1,red blue 1:3,and red blue 1:5.White light(W)is used as a control to study the effects of different LED red blue composite light quality treatments on the growth,nutritional quality,and metabolites of buckwheat sprouts,The activities of L-phenylalanine ammonia lyase(PAL),Chalcone isomerase(CHI)and Chalcone synthase(CHS)were measured.Through this project research,the impact of LED light quality on the growth,development,and nutritional quality of buckwheat sprouts and vegetables is clarified,providing scientific basis for achieving the large-scale application of high-quality LED light quality required for buckwheat sprouts and vegetables production,and providing theoretical basis for using LED light quality regulation to improve the nutritional quality of buckwheat sprouts and vegetables.The main results are as follows:1.Different soaking and germination times have an impact on the germination rate of buckwheat seeds.Under a constant temperature of 25 ℃,the soaking time is 14 hours and the germination time is 24 hours.The germination rate reaches 85%.When the soaking time exceeds20 hours,the germination rate will decrease to 40%,while when the germination time exceeds 36 hours,the germination rate shows a downward trend.2.Different LED red and blue composite light treatments have a significant impact on the growth of buckwheat sprouts and vegetables.The hypocotyl length and main root length of buckwheat sprouts under high proportion red and blue 5:1(R5B1)irradiation in the treatment group were 11.42 ± 0.85 cm and 5.63 ± 0.28 cm,significantly higher than those in the control group and other treatment groups.At the same time,the fresh weight and edible fresh weight of the whole plant in the red blue 5:1(R5B1)treatment group were significantly higher than other treatment groups.Therefore,the edible and water content of the red blue 5:1(R5B1)treatment group were also the highest among the treatment groups,reaching 89.05% and 93.62%,respectively.As the proportion of blue light increases,buckwheat malt plants will change towards shorter and thicker.The diameter of the hypocotyl of sprout vegetables under the treatment of red blue 1:5(R1B5)with the highest proportion of blue light reaches 1.78 ± 0.13 mm,significantly higher than other treatments.3.The nutritional quality of buckwheat sprouts and vegetables is greatly affected by different light quality combinations.In this study,the highest soluble protein content of buckwheat sprouts and vegetables was 4.78 ± 0.19mg/g FW under the high proportion of blue light,red blue 1:5(R1B5)treatment,and the chlorophyll content and carotenoid content of the red blue 1:5(R1B5)treatment group were also significantly higher than other treatments.Under the treatment of a high proportion of red light combined with red blue 5:1(R5B1),the maximum soluble sugar reached 7.03 ± 0.29mg/g FW.4.The trend of changes in the content of secondary metabolites such as rutin,total phenols,and total flavonoids increases with the increase of blue light ratio,all reaching their maximum values under high proportion blue light treatment of red blue 1:5(R1B5).Overall,the total phenolic and flavonoid contents of buckwheat sprouts treated with red and blue composite light were higher than those of the control group under white light(W).The measurement results of the antioxidant capacity of ABTS and DPPH showed that the antioxidant capacity increased with the increase of blue light ratio,and reached its maximum value under the treatment of red blue 1:5(R1B5).5.The determination of PAL,CHI,and CHS enzyme activities showed that with the increase of blue light ratio in the red blue composite light quality,the three enzyme activities all increased to varying degrees,and reached their maximum values under high ratio blue light red blue 1:5(R1B5)treatment.