Construction of Core Germplasm of Wild Lindera glauca Based on SSR Molecular Marker

In order to further explore and screen the germplasm resources of wild Lindera glauca in China, 18 pairs of SSR primers(5 chloroplast SSR and 13 nuclear SSR) were used in this study to analyze the SSR genotyping of 303 wild Lindera glauca germplasms from 22 natural populations that basically covered the natural distribution areas in mainland China and the genetic relationship diagram of original germplasm was drawn. The results showed that 18 pairs of primers detected Na=88. Ne was 1.18～3.76 and He was 0.14～0.74. Ho was 0～0.58 and I was 0.30～1.52, as well as PIC was 0.13～0.70. The results of STRUCTURE analysis and UPGMA clustering showed that 22 natural populations were suitable for being divided into three subgroups. The core germplasm constructed by using allele maximization(M strategy) and genetic distance maximization(SAGD) methodsat least25%(71 germplasm) and 15%(45 germplasm) sample rate, respectively could represent genetic diversity of the original germplasmon all genetic diversity indicators(t test was not significant), and conformed to the standard ofcore germplasm construction. Compared with other similar research of core germplasm, the SAGD(15% sampling ratio) was a suitable method for constructing L. glauca core germplasm. Based on n SSR markers, the retention rate of Na, Ne, and I index parameters of core germplasm constructed by 15% proportion of SAGD reached 93.24%,104.67% and 100.85% of the original germplasm, respectively. Based on cpSSR markers, the corresponding retention rate were 85.14%, 107.45% and 108.82%, respectively. And the 45 core germplasm materials screened by this method could represent the genetic diversity of the whole wild L. glauca germplasm resources in China to a certain extent. The research results herein would provide references for other core germplasm construction of non-crop woody plants, especially for species that have both asexual and sexual reproduction.