武夷山地方茶树种质生化特性和茶多糖清除超氧阴离子自由基活性分析OA北大核心CSTPCD

To explore the characteristics of main biochemical components of Wuyishan local tea germplasms and the difference of scavenging superoxide anion free radical activity of tea polysaccharides,the contents of main biochemical components of 31 Wuyishan local tea germplasm were determined.Tea polysaccharides were extracted by water extraction and alcohol precipitation method,and the SOD activity of tea polysaccharides was compared by xanthine oxidase method.The results showed that the main biochemical components of local tea germplasm in Wuyishan had strong variation and genetic diversity,and had great potential for genetic improvement.The average coefficient of variation was 21.84％,the average genetic diversity index was 2.08,and the average improvement potential was 50.92％;the contents of tea polyphenols,free amino acids,flavones,soluble sugar and the ratio of phenol to ammonia showed normal distribution.The content of tea polyphenols was significantly positively correlated with the content of flavones,and significantly negatively correlated with the content of soluble sugar.The contents of free amino acids were significantly negatively correlated with the content of soluble sugar.The first 2 principal components extracted by principal component analysis contained 81.08％information of 5 biochemical indexes,which mainly reflected the information of free amino acid and tea polyphenol content.The top 5 tea germplasms with comprehensive scores of principal components were'Baimudan''Honghaitang''Xiangtianmei''Bantianyao'and'Xiangshijiao',which could be used as good materials for breeding and promoting cultivation of high-quality Oolong tea varieties in Wuyishan tea area.Cluster analysis based on the content of biochemical components divided 31 tea germplasms into 3 categories.The 13 germplasms in groupⅠhad high content of tea polyphenols and flavones and low soluble sugar content,8 germplasms in group Ⅱ had low free amino acid content and high soluble sugar content and 10 germplasms in group Ⅲ had high phenol ammonia ratio and medium soluble sugar content.Based on the cluster analysis of tea polysaccharide SOD activity,31 tea germplasms could be divided into three categories.The SOD activity of tea polysaccharide of 8 germplasms in group Ⅰ was low,the SOD activity of tea polysaccharide of 19 germplasms in group Ⅱ was in the middle,and the SOD activity of tea polysaccharide of 4 germplasms in group Ⅲ was high.There was abundant variation in the SOD activity of tea polysaccharides,with a coefficient of variation of 40.62％and an index of genetic diversity of 2.07;the tea polysaccharides of 4 germplasm,'Baijiguan''Dahongpao''Dahongmei'and'Lingya',had high SOD activity,so their scavenging abilities of superoxide anion radicals were strong.Above results could provide a scientific basis for the improvement and utilization of tea germplasms in Wuyishan.