裸燕麦核心种质的抗氧化特性

为了解裸燕麦种质资源的抗氧化特性及其抗氧化作用的物质基础,选用和检测了120份国内外裸燕麦种质。其DPPH清除能力及总酚、生物碱和β-葡聚糖含量的变幅分别为4.34~179.98 mg L^-1、250.99~807.88 mg kg^-1、25.21~347.55 mg kg^-1和0.59%~9.69%,表现出明显的基因型差异,不同来源地和不同种质类型裸燕麦的抗氧化能力和生物碱含量差异较大。采用K-mean cluster快速聚类法将其聚为6大类群,分别由20、39、2、22、12和25份种质组成。燕麦籽粒抗氧化能力与其总酚、生物碱含量呈极显著(P＜0.01)正相关,但与β-葡聚糖含量无显著相关性。表明裸燕麦抗氧化能力与其籽粒中所含的总酚和生物碱类物质密切相关。本研究还筛选出一批高抗氧化的燕麦种质资源,有望用于高抗氧化性燕麦品种的培育。

Antioxidant Property of Naked Oat Core Collections

Naked Oat (Avena nuda L.) originated in China, has a high values in nutrition and medicine. Besides dietary fiber and nutrients, various natural antioxidants, such as phenolic compounds, phenolic acids, avenanthramides (unique to oats) and phytosterols are also contained in naked oat. All these compounds possess potential health-promoting properties, partly attributing to their antioxidant activity. Up to now, China has built the core of naked oat germplasm with the greatest diversity of naked oat types. The objective of this study was to determine the total phenol (TP), total avenanthramides (TAV), β-glucan contents and the antioxidant activity of oat cultivars from main productive areas of China as well as Former Soviet Union and North America. The correlation of antioxidant activities with contents of these components was also statistically investigated, which is benefit for oat breeding. The antioxidant activities, contents of TP, TAV, and β-glucan of 120 naked oat accessions were evaluated by Folin-Ciocalteu method, HPLC analysis and enzymatic method, respectively. Meanwhile, the antioxidant capacity was determined by 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH) scavenging ability method. Significantly genotypic variations were observed, and contents of TP, TAV, and β-glucan were 4.34–179.98 mg L^-1, 250.99–807.88 mg kg^-1, 25.21–347.55 mg kg^-1, and 0.59–9.69% respectively. The 120 accessions were clustered into six groups using K-mean cluster method, which consisted of 20, 39, 2, 22, 12, and 25 accessions respectively. There were significantly positive correlations between antioxidant activity and the contents of TP and TAV. However, the correlation between β-glucan and DPPH was not significant. These results indicated that avenanthramides contributed greatly to the antioxidant property in naked oat grains. A relative wide variations in TAV and TP contents and compositions were mainly due to differences among cultivars. Duji from Sichuan province and Yumai 38 from Qinghai province with high contents of TP and TAV are expected to be used in further quality breeding of naked oat.