Comparative Research On Identification Methods Between DUS Test And SSR Molecular Marker In Barley

Barley belongs to cereal crops and ranks the fourth most widely cultivated and utilized cereal worldwide after rice,wheat and maize.Though barley is an important crop,it can access to the market without any certification in China,causing more and more barley varieties accessing to the market.Most varieties with closely genetic background share the similar morphology characters.As a result,illegal phenomena impeded the development of seed industry.In the present study,Forty-four barley varieties originated from domestic and overseas were used.By their geographical origins,Forty-four barley varieties were clustered into three categories,including local relevant barley varieties group,domestic barley varieties group and overseas barley varieties group.According to the agriculture industry standard'NY/T2224-2012',“Guidelines for the specificity,consistency and stability of new plant varieties-barley",38 characters were investigated and analysis by DUS test method.Twenty eight SSR markers distributed evenly on the 7 chromosomes were used to analyze the genetic diversity and distinctness of barley varieties in the three categories.Consistency and difference were compared between DUS and SSR methods.The main results were as follow:1.The consistency,stability and specificity of 44 barley varieties were detected by DUS test.Ten traits including awn length,length of flag leaf,angle of flag,etc.were removed due to bad specificity,consistency and stability.Finally,we remained 21 qualitative traits and 7 quantitative traits were used to identify different kinds of barley varieties.2.A total of 83 variation types and the average of the 2.964 variation types and variation range from 1.047 to 4.24 were detected in 44 barley varieties by selected 28 traits,and indicating that rich variation exist in the 28 traits among the 44 barley varieties.Twenty eight traits could be differentiating three different types of barley varieties originated from domestic and overseas.3.A total of 102 alleles were detected in 44 barley varieties by using twenty-eight SSR markers.The number of loci each marker had ranged from 2 to 6 with an average of 3.64,the PIC value each marker had ranged from 0.08 to 0.77 with an average of 0.45,which indicated that the 28 markers had high polymorphism.4.At least 7 SSR markers were required in order to identify the barley varieties from Jiangsu province,Zhejiang province and Shanghai province by using the Matlab software programming.At least 6 SSR markers were required to distinguish domestic barley varieties.Identification of overseas barley varieties required at least 6 SSR markers.Identification of domestic and overseas barley varieties required at least 14 SSR markers.5.The correlation was not significant between the DUS test and SSR molecular markers methods of barley varieties in the three categories Compared with DUS test,SSR molecular marker method was more suitable for the identification of varieties,because of its fast,short testing time and the results is more accurate.However,the SSR molecular marker method required high technical and costs.DUS test was still utilized as a significant method in authenticity and purity identification.Nevertheless,it insist we strictly take control of field experiment conditions and master standards as well as appraisal periods related to the agronomic traits.