Objective A method to verify authenticity of an Oncidium hybrid progeny was developed based on the EST-SSR and SRAP molecular markers for cultivar selection at early stage.
Method In this study, Wil. ‘Rich Yellow’, Onc. ‘Million Dollar’ and their 46 hybrid progenies were used as test materials. The effective primers with patermal characteristic bands, while the bands were clear and stable, were screened from 21 pairs of EST-SSR primers and 176 pairs of SRAP primer combinations. Then, the selected effective primers were used to amplify the test materials. According to the amplification results, the authenticity identification, cluster analysis and genetic similarity coefficient analysis of the hybrid progenies were carried out.
Result Six pairs of EST-SSR primers and 10 pairs of SRAP primer combinations were chosen for the verification on 46 hybrid progenies. From the EST-SSR primers 34 polymorphic bands were obtained with 87.18% polymorphic loci, while the SRAP primer combinations rendered 81 polymorphic bands with 81.82% polymorphic loci. From the clustering results, we can see that all the hybrid progeny strains were closely related to the female parent. The average genetic similarity coefficient between hybrid progenies and female was higher than that of the male parent, indicating that the hybrid progenies are closer to female parent in heredity, which was consistent with the results of clustering analysis.
Conclusion EST-SSR and SRAP molecular markers can be effectively used in the study of authenticity identification of hybrid progenies of Oncidium hybridum.
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