| Ailao Mountain is located in the central part of Yunnan Province,from the south of Dali Prefecture in the north to the southern end of Honghe Prefecture in the south.It is one of the important sources of tea.Steamed green solid samples of mature leaves and fresh leaves of two and three buds were selected as research materials,and the phenotypic characters of leaves were standardized and assigned.Water extract content,amino acid content,tea polyphenol content,total flavonoid substance,caffeine content,catechin component and theophylline content of test materials were determined by conventional method and high performance liquid chromatography.Based on the obtained biochemical results,the genetic diversity,biochemical content difference and quality characteristics of test materials in different regions were analyzed based on principal component and cluster analysis.At the same time,the adaptability and propagation path of ancient tea tree in Ailao Mountain region were speculated.The main research results are as follows:1.Through investigation and analysis of 8 phenotypic characters of leaves of ancient tea tree resources in Ailao Mountain region,high genetic diversity and rich variation types were found in this region.From the perspective of numerical characters,leaf length ranges from 7.20 to 23.50 cm,leaf width from 3.18 to 9.04 cm,leaf area from 17.24 to 148.71cm2,vein logarithm from 6 to 13,and the average diversity index is 0.71.The coefficient of variation was 27.45%.In terms of descriptive characters,the leaf size showed large leaf,very large leaf,and the leaf shape was mainly oval and long oval.The leaf tips are acuminate and the density of leaf teeth is shallow.The coefficient of variation was 22.05%and the diversity index was 1.90.The phenotypic trait genetic diversity of ancient tea tree resources in Zhenyuan County and Jinping County is rich,and the potential for selection and breeding is large,which can provide abundant tea tree germplasm resources.2.There was a rich variation in the content of the main biochemical components of ancient tea tree resources.The average contents of water extracts,amino acids,tea polyphenols,caffeine,flavonoids and theophylline were 51.00%,4.18%,32.91%,29.17mg/g,8.55 mg/g and 0.53 mg/g,respectively,and the average contents of catechins C,EC,ECG,CG,EGC,EGCG,GC,GCG and total catechins were 14.12 mg/g,12.65mg/g,28.43mg/g,0.61mg/g,16.98 mg/g,77.72 mg/g,52.03 mg/g,2.43 mg/g and 205.06 mg/g,The average contents of water extracts of ancient tea tree resources at different sampling sites ranged from 47.29 % to 54.07 %,amino acid contents from 3.12 % to 4.84 %,and polyphenol contents from 31.39 % to 34.67 %.Caffeine content 25.35 mg/g to 39.30 mg/g,total flavonoids 7.78 mg/g to 9.60 mg/g,theophylline 0.29 mg/g to 1.02 mg/g.C content ranged from 7.80 mg/g to 25.08 mg/g,EC content ranged from 4.74 mg/g to 28.30 mg/g and ECG content ranged from 14.83 mg/g to 52.83 mg/g.14.83 mg/g to 52.34 mg/g,CG content 0.37 mg/g to 1.05 mg/g,EGC content 13.45 mg/g to 20.33 mg/g,EGCG content64.88 mg/g to 95.81 mg/g,GC content 32.05 mg/g to 77.10 mg/g,GCG content 1.28 The coefficients of variation of the 15 biochemical components ranged from 6.11% to 91.65%,with an average coefficient of variation of 61.31%,the largest coefficient of variation being EC and the smallest being water leachate content.This indicates that EC has a higher potential for improvement and water leachate a smaller one.The average diversity index of the test tea samples was 1.88,with a range of variation from 1.45 to 2.14,showing a rich biochemical diversity.3.Based on results of principal component analysis,it was found that the cumulative contribution of the five principal components was 77.74%,which could summarize most of the genetic information of 110 ancient tea tree resources.EC contributed more to the first principal component,followed by ECG and CG.The 3rd,4th and 5 principal components contributed tea polyphenols,water extract and theophylline,respectively.Based on the results of cluster analysis results,110 samples of ancient tea tree resources were grouped into two groups,two samples(Badizhai 22 and Shitouzhai 6)were grouped into one group,and the rest were grouped into one group.When the Euclidian distance was 10,the first group was divided into four subgroups.The tea samples collected from Zhenyuan County were mainly distributed in group A2,and the average value of the eight biochemical components,namely water extract,caffeine,flavonoids,C,EC,ECG,CG and EGC,was the highest among the four subgroups.4.In terms of the content of non-ester catechin such as C and EC,which reflect the evolutionary degree of tea trees,the content in the old seawall in Zhenyuan County was the highest and the content in Jinping County was the lowest.Combined with PLS-DA results showed that the test tea samples collected from the old seawall were more original than other sampling sites.This study concludes that the tea area in Zhenyuan County is closer to the original distribution area of tea tree compared with Jinping County,and it is speculated that tea tree may spread from the central part of Mao Luo Mountain to the south.5.From the perspective of phenolic ammonia ratio and catechin quality index,most of the ancient tea trees in Jinping County are suitable for green tea.Among them,the ammonia ratio of four ancient tea trees in Jiwozhai area is more than 15,which is suitable for black tea.Zhenyuan County ancient tea tree resources red green tea and system.6.According to the provisions of biochemical indexes in agricultural industry standards,7 samples of low caffeine(content ≤1.5%)were selected from 110 samples of ancient tea tree resources.There were 38 materials with high amino acid(content ≥5%),109 materials with high tea polyphenols(content ≥25%)and 63 materials with high catechin(total content ≥20%).One ancient tea tree resource had the specificity of low caffeine base,high tea polyphenols and high catechin,two had the specificity of high amino acid,high tea polyphenols and low caffeine base,and three had the specificity of high tea polyphenols and low caffeine base. |
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