Abstract:

SSR markers were used to identify 14 poplar varieties, including 4 varieties of Populus deltoides, 2 varieties of Populus nigra and 3 transgenic varieties of the same species, 2 hybrid varieties, 'Senhai 1' and 'Senhai 2', of P. deltoides '55/65' × P. cathayana and 2 hybrid varieties, 'Danhong' and 'Juba', of P. deltoides '55/65' × P. deltoides'2KEN8', by using capillary electrophoresis with fluorescence detection. A total of 58 primers were screened to detect differences of SSR markers among the varieties. The 4 varieties of P. deltoides were distinguished by 4 primers, the 5 varieties of P. nigra were distinguished by 5 primers, and the hybrid varieties of the 2 crosses were identified by 4 primers. Varieties of Aigeiros and Tacamahaca displayed their own unique peaks in 4 SSR loci (GCPM_1574, GCPM_1155, GCPM_1293 and GCPM_1502). P. deltoides and P. nigra were found significantly different at the SSR loci. There were different SSR genotypes between the transgenic and non-transgenic varieties of P. nigra. The results indicated that the SSR markers are reliable for identifying those poplar varieties including transgenic varieties. The pedigree analysis of poplar hybrids revealed that the hybrid variety 'Danhong'had 2 peaks of 109 bp and 129 bp at 2 SSR loci (GCPM_1037 and GCPM_1376) that did not exist in its parents, indicating possible pollen contamination occurred during the pollination process.

Key words: Poplar(Populus), SSR, capillary electrophoresis, fluorescent detection, varieties identification