Analysis and Identification of Section Aigeiros Germplasm Based on SSR Molecular Markers

The genetic diversity analysis and identification were carried out on 50 section Aigeiros germplasm with 15 pairs of SSR primers screened, and the dendrogram was constructed to conduct genetic relationship analysis based on genetic similarity coefficients. The results showed that a total of 187 polymorphic loci were detected with 15 pairs of primers, and the percentage of polymorphic loci was 100%. The number of polymorphic loci detected by each pair of primers ranged from 8 to 19 with an average of 12.47. The average expected heterozygosity(H_e) was 0.8207, and the observed heterozygosity(H_o) averaged 0.7391. The average polymorphism information content(PIC) was 0.79. Among them, 12 pairs of primers detected specific sites in 17 samples, a total of 36 specific sites were detected, and the number of specific sites was detected by each pair of primers ranged from 1 to 5. UPGMA cluster analysis was performed on 50 poplar germplasm. The genetic similarity coefficient ranged from 0.7273 to 0.9893 with an average of 0.8045, have high genetic similarity. When the similarity coefficient was 0.79, the samples could be divided into 4 categories, and the cluster analysis results were consistent with the genealogical relationship and introduction provenance of germplasm, which could better reflect the genetic relationship between germplasm. Based on the results of specific site detection and cluster analysis, it was preliminarily determined that N024, N018, N017, N009, YN and 47# may not be pure P. deltoides, and that N4 and N51 may not be pure P. nigra, which needs further verification. According to the allelic site characteristics of each primer, the primer combinations GCPM-2826, P139, P3 and P141 were selected to construct the fingerprint of 14 germplasm, which could effectively distinguish 14 germplasm.