Strategy for the construction of a core collection for Pinus yunnanensis Franch. to optimize timber based on combined phenotype and molecular marker data

The core collection construction strategies are critical for the conservation and utilization of germplasm resources. The combined data of phenotypic characteristics and SRAP markers in 780 samples were employed to construct a core collection for Pinus yunnanensis Franch. Based on geographical distribution, a total of four P. y unnanensis germplasm subsets were configured by improving a least distance stepwise sampling method at four sampling proportions. The representativeness of germplasm subsets for original germplasms were evaluated by quantitative and qualitative trait independence tests. For the quantitative traits test, the germplasm subset at a 30% sampling proportion was the best of four germplasm subsets by the mean t -test, the variance F -test, the frequency distribution χ 2 -test, the Shannon diversity index, and five effective evaluation parameters. For the qualitative traits test, there were significant differences between the original germplasm and germplasm subset at a 10% sampling proportion in the mean t -test of genetic diversity indicators. The genetic diversity within the population was significantly different between the original germplasm and germplasm subsets at 20% and 10% sampling proportions, respectively, in the variance F -test. The results of quantitative and qualitative traits tests revealed that the 30% sampling proportion was appropriate for the construction of the core collection.