SSR Markers-based Cotton Purity And Anthenticity Identification

Test of cotton variety authenticity and seed purity is the source of law,which involves variety right protection,seed quality detection and market supervision. The result of official survey shows: there are dozens of newly approved cotton varieties each year and about 500 long-term cultivated cotton varieties in China. However, the matched detection technology still stays in the phase of cultivation appraisal. Though there are a great number of reports related to the cotton seed purity authentification in recent years,the reported technologies still have been not applied to practice.DNA fingerprint map construction of cotton seed is the premise of cotton seed identification . The SSR molecular marker technology is increasingly perfect, which lays the function for its application on variety detection. The aim of the study is to explore feasible way to bring SSR molecular marker to detect cotton seed and the key technology on the DNA fingerprint map construction of cotton seed. In the study, the DNA fingerprint map of 86 cotton seeds wasconstructed. All of them provide theoretical basis for dividing the relationship of germplasm resources in cotton and breeding new variety.The main conclusions are summarized as follows:1. This study investigates some key steps of SSR molecular maker based cotton seed detection from the following aspects: DNA extracting, PCR amplification, PAGE and sliver dyeing. As a consequence, an identification system of DNA fingerprint of cotton is established initially with the principle of high speed dispensing, accuracy and stabilization.2. From CMD database, Cotton DB database and documents , 409 pairs of primers, Which have unit point , located in chromosomes and are filtered again in lab. With 21 basic germplasms, the kay 25 pairs of polymorphic primers with suitable amplification and high resolution were screened from 409 pairs of primers.3. The fingerprint of 21 basic germplasms, 31 standard varieties and 33 major cultivars were constructed separately. The latter two are clustered and analyzed through NTSYS-PC V2.1 analysis software.4. The authenticity and purity of cotton seed was checked and analyzed based on the DNA fingerprint map. The date from lab test and those from field identification are compared and analyzed. The results showed that the variety authenticity of lab detection is consistent with the data of field indentification, The results reveal:the relavant index (R) is 0.6067 which indicates the relevance of the samples reaches the significant level.5. The reason for the different data between lab test and field identification was analyzed. In addition, the possible avenue of cotton seed purity and authentification identification based on DNA map was explored.