Effects Of Low Dose UV-B On Morphological Development And Bioactive Components Of Common Buckwheat Sprouts

Buckwheat sprouts are new vegetables cultivated by soilless culture techniques.They mainly refer to the use of buckwheat seeds to cultivate young shoots,seedlings and vegetables for human consumption under suitable conditions.Buckwheat sprouts are rich in nutrients,which are rich in anthocyanins and rutin,and studies have shown that the content of rutin is 3 to 31 times that of seeds after germination.Studies have shown that rutin in buckwheat has the effect of reducing capillary permeability and fragility,maintaining and restoring the normal elasticity of capillaries,and can be used to prevent hypertension.In addition,D-chiro-inositol（DCI）is mainly found in plants such as buckwheat and soybean,which can effectively regulate blood sugar and improve the ovulation of patients with polycystic ovary syndrome（PCOS）.If the body lacks DCI,insulin resistance will occur.Previous studies on DCI mainly showed the mechanism of DCI acting on animals,but there were not many studies on how to improve DCI in plants.Compounds such as rutin and anthocyanin in buckwheat will increase sharply after exposure to ultraviolet light.Based on this characteristic,we use buckwheat as raw material and UV-B as a light regulator in our study.The aim of this study was to investigate the effects of different doses of UV-B radiation on the accumulation of anthocyanins,vitamin C,rutin,flavonoids and DCI in buckwheat sprouts,and to carry out the cross section of hypocotyls of buckwheat sprouts through microscopic observation.It provides a theoretical basis for the development and utilization of buckwheat sprouts agricultural products.The research content and research structure are as follows:1.The optimum conditions for the germination of buckwheat were studied.The germination process of buckwheat went through five parts:seed selection,invasive breeding,germination,code tray and watering culture.The germination rate of buckwheat seeds was used as the evaluation index,and the germination of buckwheat seeds was finally established.The best process conditions.The results showed that:the seeds were immersed in 40°C water for 30 minutes,and then immersed in a normal temperature at 25°C for 24hours,and the germination rate was highest at 27°C in an incubator.2.The effect of UV-B on the morphological development of buckwheat sprouts was studied.UV-B stress significantly inhibited the hypocotyl length of buckwheat sprouts.The UV-B at 7 hours was 16.82%lower than that of the control buckwheat bud hypocotyl,but UV-B irradiation on the hypocotyl of buckwheat buds.There was a significant increase in diameter,which increased by 15.38%compared to the control at 3 hours.By measuring the fresh weight of buckwheat sprouts,it was found that the total weight did not decrease.It shows that a small amount of UV-B irradiation can ensure that the yield is unchanged or it can be made thick and short,and the mouthfeel is good.3.The effect of UV-B on secondary metabolism of buckwheat sprouts was studied.In this experiment,low dose UV-B irradiation can increase the content of rutin,D-chiral inositol,anthocyanin,flavonoids and polyphenols in buckwheat buds,but with the increase of UV-B irradiation time,the content of these substances generally increased first and then decreased.By observing the cross-sectional view of hypocotyls of buckwheat sprouts,it was found that anthocyanins mainly existed in the epidermal cells of hypocotyls,several parenchyma cells in the near epidermis.Compared with the control group,low-dose UV-B irradiation had the greatest increase in secondary metabolism of buckwheat buds.High-dose UV-B irradiation not only affected the content of secondary metabolism but also affected morphological development.Therefore,according to the above experimental results,in terms of maintaining the quality of buckwheat sprouts and increasing the content of antioxidant substances,if only considering increasing anthocyanin content,the optimal irradiation time of UV-B is 3h(2.592 kJ m^-2).The optimal irradiation time of UV-B is 5h(4.32 kJ m^-2)when considering only the content of rutin and vitamin C.When considering the content of D-chiral inositol,flavonoids and polyphenols The optimal irradiation time for UV-B is 6h(5.184 kJ m^-2)4.The effect of UV-B on secondary metabolism related enzymes of buckwheat sprouts was studied.UV-B can affect the activity of anabolic enzymes related to antioxidants to varying degrees.PAL and CHI enzymes increase first and then decrease with UV-B stress,which is related to total polyphenols and reeds in malt.The content of butyl and flavonoids has the same tendency.