Evaluation And Analysis Of 45 Grapefruit Germplasm Resources

Pomelo have about 3000 years of cultivation history in China.It originated from China and has courful genetic variation,long-term use of natural resources to cultivate and create a lot of excellent varieties,rich germplasm resources of citrus grandis.Fujian province is located in the southeast coastal area of China,and its subtropical monsoon climate is very suitable for the growth of pomelo.However,due to various types of shaddock complex shape,and prone to mutation,the genetic background of fuzzy hampered the breeding process of pummelo in a certain extent.In view of this,this study was carried out to analyze and evaluate the germplasm resources of pomelo in Fujian,which provided a scientific basis for the genetic evolution,classification and development of germplasm resources.This study includes the following aspects:1.The botanical characteristics of the grapefruit germplasm resources are diverse,the tree shape is rounded,oval,umbellate and irregular;the growth of the tree shows strong,medium and weak;the shape of leaf has broad oval,long oval;the shape of the fruit is pear-shaped,spherical,obovate;the color of the flesh is white,red,yellow and so on.2.The ripening period of the grapefruit fruit of June pomelo is relatively early compared with other breeds,and the maturity of the Taiwan and Sichuan late short pomelo is relatively late,which may be related to the characteristics of the pomelo itself or the geographical location.According to the different maturity of the fruit,you can take the corresponding measures in the production,in order to extend the supply period of the early market by increasing the proportion of early or late maturing varieties,and it may improve the economic benefits of the pomelo industry.3.The contents of pomelo,such as,soluble sugar,organic acid,Vc and soluble solids were determined by measuring the chemical composition of pomelo,the content of organic acids in 45 pomelo resources was 0.33%?1.28%;the contents of soluble solid was 7.9%?12.1%;the content of soluble sugar was concentrated in the range of 5.8%?8.9%;the content of Vc was concentrated at 13.27mg/100g?53.58mg/100g,And three excellent varieties were selected accord to the appearance and quality of pomelo:Huangrou pomelo,Hongmian pomelo,June pomelo.4.Collection of grapefruit leaves and extract DNA,for pomelo-rich phenolic and polysaccharide substances using modified CTAB method.The experimental results show that the extracted DNA meets the requirements of subsequent amplification in terms of concentration and purity.In the reaction system with 20 ?L final volume,the genomic DNA template was 20 ng,the dNTPs was 0.25 mmol/L,the Primer was 0.25 ?mol/L,the Taq enzyme was 0.5U,lO×Buffer 3?L,the rest with ddH2O added.5.A total of 15 primers were screened out from 100 primers and 45 fruiting germplasm resources were amplified by PCR.159 bands were amplified,including 144 polymorphic bands,polymorphic ratio 90.57%,and the similarity coefficient of 45 grapefruit germplasm was between 0.50 and 0.92.The results showed the genetic diversity of 45 grapefruit germplasm in Fujian.This can lay a theoretical foundation for more efficient breeding and introduction.6.The evaluation of the new varieties of pomelo breeding,radiation mutation breeding and hybrid breeding and other aspects of the use of the prospects,through comparison,with a view to screening out some high quality varieties and suitable for cultivation in the surrounding areas of Fujian.