Character Evaluation And Genetic Diversity Analysis Of Chinese Buckwheat Germplasm Resources

Buckwheat belongs to Polygonaceae and Fagopyrum.As the origin and diversity center of buckwheat in the world,China contains abundant buckwheat germplasm resources.Since the 1980 s,the Institute of crop science,Chinese Academy of Agricultural Sciences,together with a number of scientific research institutions in China,has collected more than 1500 common buckwheat germplasm resources.In this study,the agronomic characteristics of buckwheat in China were analyzed systematically.The variation of total flavonoids in buckwheat seeds was determined by aluminum trichloride method and rutin in buckwheat seeds by liquid chromatography.Finally,the core collection of buckwheat was constructed by SSR molecular markers combined with the existing source information and some phenotypic traits.The main conclusions are as follows:1.In the evaluation of buckwheat Germplasm Resources(1)The germplasm resources of common buckwheat in China are very extensive.The longitude range of 1287 buckwheat materials used by the research is 41° 23′～42°30’,longitude East114°48′～123°34’,it is concluded that the most common buckwheat producing areas in China are basically covered.(2)The phenotypic variation of buckwheat germplasm resources in China is large.The main biological characters(flowering period,plant height,stem length,stem diameter,number of primary lateral branches,node number of main stem,leaf length,leaf width,color of main stem,flower color and leaf vein color)and related indexes(1000 grain weigh,seed length,seed width,seed length / width,seed perimeter)of buckwheat showed varying degrees of variation,which were the core germplasm resources of buckwheat.It provides a solid foundation for the construction of genetic resources and molecular breeding.(3)In the correlation analysis of agronomic traits,the study found that: stem length and plant height,the mean perimeter of seeds and the mean length / width of seeds have a high correlation;while leaf length and leaf width of leaves,stem node and stem length,plant height,stem diameter,branch number have a certain correlation.2.In the analysis of total flavonoids and rutin content of buckwheat Germplasm Resources(1)In this study,we have heard of the establishment of an effective method to monitor the content of rutin in Buckwheat by liquid chromatography and carried out the methodological verification of the method from the specificity,precision,stability,repeatability and sample recovery test.(2)In this study,aqueous solution and acetonitrile solution(containing 0.4% phosphoric acid)were used as mobile phases to gradient elute buckwheat sample solution.The variation range of flavonoids in buckwheat germplasm resources in China was systematically analyzed.The results showed that: the average content of rutin in buckwheat seeds was 0.310 mg/g,the highest could reach 1.780 mg/g,and the lowest only contained 0.017 mg/g,most of which were concentrated in the range of 0.100-0.400 mg/g.It showed a large variation range.(3)In this study,the content of total flavonoids in buckwheat seeds was determined by aluminum trichloride method.The results showed that the highest content of total flavonoids in buckwheat seeds could reach 7.940 mg/g,the lowest was only 0.070 mg/g,and the average value was 2.840 mg/g.The content of total flavonoids mostly concentrated in the range of 2.000-4.000 mg/g.It showed a large variation range.(4)Correlation analysis showed that: the correlation coefficient between total flavonoids and rutin in buckwheat seeds was 0.351,and showed a significant level of 0.05,which indicated that there was a significant positive correlation between total flavonoids and rutin content in buckwheat seeds.3.Construction of Core Germplasm Bank of Fagopyrum esculentum.In this study,the genetic diversity of 1287 buckwheat germplasm resources were evaluated by using the source information,phenotypic traits and 7 pairs of SSR markers,and 530 buckwheat primary core germplasm banks were constructed.All the materials were divided into five groups by SSR clustering,most of them were concentrated in the fifth subgroup,and the rest showed certain regional characteristics.SSR marker analysis showed that the similarity coefficient of 1287 accessions ranged from 0.048 to 0.949,with an average of 0.429.Cluster analysis based on SSR molecular markers showed that there was a certain correlation between germplasm resources and their geographical distribution.