Study On Effect Of Genotype And Environment On Contents Of Tocopherols And Optimization Of Extraction Of Flavonoids In Barley Kernels

The tocopherol which has prominent effect on consenescence retard and anti-disease is one of requisite vitamins sustaining human normal metabolism. Flavonoid is one of secondary metabolites in plant, which has important effect on the metabolism of human, animal and plant. There are many kinds of active constitutents in barley kernels, such as tocopherol, flavonoid, polyphenol. The tocopherols in barley kernels were extracted using ultrasonic method and determined using high-performance liquid chromatography to understand the effect of cultivation measures, genotype and environment on the content of tocopherols and their quantitative inheritance. Furthermore, the extraction technology of total flavonoids from barley kernels was optimized. The results as follows:1. Effect of genotype and environment on contents of tocopherols in barley kernelsThe contents of tocopherols in barley kernels of 7 cultivars planted in 3 different natural ecosystems were determined. The results showed that the contents among genotypes, among eological sites and the interaction beteween genotype and environment differred significantly. The genotypic effect on contents ofα,γ, d and total tocopherol were higher than that of environment, while genotypic effect on content ofβ-tocopherol was lower than that of environment.2. Effect of cultivation measures on the contents of tocopherols in barley kernelsThe contents of tocopherol in barley kernels of 10 cultivars planted under different application rates of nitrogen fertilizer, different timings of nitrogen fertilizer, different sowing dates and different irrigation quantities were determined using split plot design. The results showed that the contents ofα,β,γand total tocopherol were dramatically affected by application rates of nitrogen fertilizer. The contents ofβ,γand total tocopherol were increased significantly with the increase of application rates of nitrogen fertilizer. The content of a-tocopherol also increased, but not significantly. The content of d-tocopherol dramatically decreased with the increase of application rates of nitrogen fertilizer. The effect of cultivars on the contents ofα,β,γ.δand total tocopherol were higher than that of application rates of nitrogen fertilizer. Compared with application of nitrogen fertilizer at seedling stage and grouting stage, the application of nitrogen fertilizer at shooting stage can significantly incease the contents ofα,β,γ,δand total tocopherol. The effect of cultivars on the contents ofα,β,γand total tocopherol were higher than that of application timings of nitrogen fertilizer, whereas the difference of content of d-tocopherol was codetermined by the application timings of nitrogen fertilizer and cultivars. Sowing date had significant influence on the contents ofα,β,γ,δand total tocopherol. The contents ofβ,γ,δand total tocopherol decreased with the sowing date postponed. The effect of cultivars on the contents ofα,β,γ,δand total tocopherol were higher than that of sowing dates. Irrigation quantities had significantly influence on the contents ofα,β,γ,δand total tocopherol. Drought and excessive irrigation can significantly increase the contents ofα,β,γ.δand total tocopherol. The effect of cultivars on the contents ofβand d-tocopherols were higher than that of irrigation quantities, whereas the difference of contents of a, y and total tocopherols were codetennined by the irrigation quantities and cultivars.3. Quantitative inheritance of contents of tocopherols in barley kernelsThe quantitative inheritance of contents of tocopherols in barley kernels was studied by using complete diallel crossing design from 6 barley parents differd in the contents of tocopherols. The results showed that I109M055M is a good parent for high contents of tocopherol. The content of a-tocopherol was mainly controlled by dominant effect, while the contents ofβ,γandδ-tocopherol were controlled by additive effect. The heritability of the contents ofα,β,γ,δand total tocopherol were significant. The broad heritabilities of the contents ofα,β,γ,δand total tocopherol were higher, whereas the narrow heritability of the content of a-tocopherol was lower.4. Optimization of the ultrasonic-assisted extraction of total flavonoids from barley kernelsUsing the defatted barley powder as raw materials, the ultrasound-assisted extraction of total flavonoids from barley kernels was optimized by the response surface methodology. Results showed that ethanol concentration and ultrasonic time were significant(p<0.01) factors on the extraction yield of total flavonoids. The optimal conditions for the ultrasound-assisted extraction of total flavonoids from barley kernels were established as follow:ethanol concentration,95%; ratio of solvent to material,55mL/g; ultrasonic time,22min, and extraction temprature,50℃. Under these conditions, the extraction yield of total flavonoids could reach to a theoretic value of 0.80mg/g.