Identification Of Cotton Varieties And Construction Of Variety ID By Using SSR Markers

Cotton is one of the important economic crops in china. Excellent variety is the key factor for quality and high yield of cotton. As the rapid development of seed market, the diversification of breeding and management subject were promoted, and varieties with the phenomenon of "deck" and "fake" also emerged. It not only brought difficulties and confusions for cotton breeding, testing and variety rights protecting, but had lead to serious damage for the production of cotton. With the limited of breeding parents, the genetic similarity of varieties was becoming closer, and it was hard to distinguish by morphological identification. In this article,39 pairs of SSR primers had been screened and were used for establishing the technology system for cotton variety identification. In other hands, the construction scheme for cotton variety ID was designed, and bar code or QR code of the variety ID was structured for 150 cotton germplasm resources. The main results were as follows:1、By optimizing the components of PCR reaction system and the procedure of amplification, a set of suitable methods was determined for SSR markers analysis.2、391 pairs of SSR markers were chosen from CMD.39 pairs of primers with high polymorphism and good repeatability and even distribution evenly on 26 chromosomes of cotton were screened by 95 cotton base germplasm resourses.3、39 pairs of core primers were used to analyze the genetic diversity of 95 base germplasm resourses. In the similarity coefficient of 0.73, these germplasm resources were divided into four groups, which had identified with pedigree analysis.4、39 pairs of SSR primers were used for the identification of 16 cotton varieties with different sources. The sampling mode was determined by comparing the genetic information of different sampling. The result revealed that there were three types of SSR genotypes among different samples:the identical type, the suspected identical and the distinct type. Based on the analysis for distinct locus threshold from various varieties, the samples could be determined as different varieties when the distinct locus was more than 2, while the samples could be determined as similar varieties when the distinct locus was less than 2.5、Referring to the construction of human ID, the commodity information, molecular fingerprinting information and the specific genetic information were combined to construct cotton variety ID.150 cotton varieties’ ID was constructed according to the scheme, and was converted into the corresponding bar code and QR code by specific software.