Study On Genetic Diversity Of Pitaya Based On SSR Molecuclar Marker

This experiment used SSR molecular markers to study the genetic diversity of 96 Pitaya germplasm resources from Nanning,Guangxi,Guilin,Bama,Guangxi,Conghua,and Qionghai,Hainan,and electrophoresis on 4%agarose gel Detection of amplification products;observation and recording of phenotypic traits of 96 Pitaya germplasm resources at the same time,hoping to rely on the advantages of molecular technology to accurately and effectively identify some Pitaya germplasm resources to combat adulteration and protect fire Pitaya germplasm resources are of great significance and provide data information for the selection and breeding of new fine Pitaya varieties.The results of this experiment are as follows:(1)The extraction of DNA from pitaya was unstable due to its high polysaccharide content.By referring to the relevant literature and improving the CTAB method as follow,the same volume of 10%kAc as isopropyl alcohol was added in the fifth step of the extraction method,and the adsorption column physics was added in the seventh to twelfth steps.After filtering,the extracted DNA samples meet the requirements of the next experiment in terms of concentration and purity.(2)Pitaya SSR Experiment System.In order to ensure the ideal experimental results,the experiment was optimized in advance for the SSR-PCR reaction system,SSR-PCR amplification program,and agarose gel electrophoresis system.The results obtained by the optimization of the experimental system meet the requirements of this experiment.(3)Screening of SSR core primers.Using the optimized SSR experiment system,20 pairs of SSR core primers with good reproducibility,clear band identification and good polymorphism were selected from 100 pairs of SSR primers.(4)Using 20 pairs of Pitaya SSR core primers to conduct a diversity study on 96 dragon fruit germplasm resources,a total of 109 clearly identifiable bands were obtained,and the DNA fragment size after PCR amplification was between 100-350bp,each pair The primers can amplify 3-8 bands with diversity.On average,each pair of primers can amplify about 5 bands with diversity characteristics.When the Jaccard coefficient is 0.700,the 96 Pitaya resources can be roughly Divided into 6 categories.It shows that SSR molecular marker is suitable for the identification of Pitaya varieties.