Primary Study On Authenticity And Purity Detection Of Rapeseed Hybrids Using SSR Markers

The authenticity and purity identification technique has always been one of the most concerned issues for crop variety administration depatment, breeding institutions and seed companies.The technique of SSR molecular markers to identify the authenticity and purity of rice and maize has already been promulgated by the national government, but in rapeseed, the core primers have not been determined.In our research group, SSR markers have been used to evaluate the polymorphism of the core parents of Brassica napus and the comprehensive database of strain marker genotype was established. On this base, core primers were further identified to establish the system of authenticity and purity identification for hybrid seeds, which would provide a set of core primers to identify the authenticity of varieties. At the same time, the primers that can precisely and quickly identify the hybrids of Huayouza series needed to selected, which could identify the purity of Brassica napus hybrids in our institution.1. Based on the principles of stable amplification, simple and clear bands, rich allelic variation and well-distributed in the chromosomes,38pairs of core primers (2of each chromosome) and19extended primers (1of each chromosome) were selected from the173pairs of primers screened in our lab before.2. By using the75varieties of winter oilseed rape in the official regional trial of Hubei Province in2011-2012as experiment materials, the38pairs of core primers were evaluated. As a result,141polymorphic loci were detected and the average polymorphism information content (PIC) was0.61. The genetic similarity comparison between varieties showed that58varieties were highly or relatively high specific with genetic similarity coefficient<85%,13varieties were medium specific with genetic similarity coefficient between85%and90%, and4varieties were lower specific with genetic similarity coefficient>90%. This set of primers could distinguish the75varieties completely and could be used as the reference primers for rapeseed authenticity identification.3. Taking the core parents in our institution as experiment materials and based on the principles of stable amplification, simple and clear bands, co-dominance and appropriate length of amplification segment, the specific primers for each of14hybrid combinations were screened out. Then these primers were used to identify the purity of each hybrid combination with190individuals.. After that, the fertility of each individual was checked by traditional field investigation. The results showed that most primers’ matching rates were over90%. Meantime, the optimal and alternative primers for purity identification for the14hybrid varieties were determined according to the matching rate.