Simple Genetic Distance-Optimized Field Deployments for Clonal Seed Orchards Based on Microsatellite Markers: As a Case of Chinese Pine Seed Orchard

Abstract

Chinese pine seed orchards are in a period of transition from first-generation to advanced-generations. How to effectively select populations for second-generation seed orchards and significantly increase genetic gain through rational deployment have become major issues. In this study, we examined open- and control-pollinated progeny of the first-generation Chinese pine seed orchards in Zhengning (Gansu Province, China) and Xixian (Shanxi Province, China) to address issues related to phenotypic selection for high volume growth, genetic diversity analysis and genetic distance-based phylogenetic analysis of the selections by simple sequence repeats (SSRs), and phylogenetic relationship-based field deployment for advanced-generation orchards. In total, 40, 28, 20, and 13 superior individuals were selected from the large-scale no-pedigree open-pollinated progeny of Zhengning (ZN-NP), open-pollinated families of Zhengning (ZN-OP), open-pollinated families of Xixian (XX-OP), and control-pollinated families of Xixian, with mean volume dominance ratios of 0.83, 0.15, 0.25, and 0.20, respectively. Phylogenetic relationship analysis of the ZN-NP and XX-OP populations showed that the 40 superior individuals in the ZN-NP selected population belonged to 23 families and could be further divided into five phylogenetic groups, and that families in the same group were closely related. Similarly, 20 families in the XX-OP population were related to varying degrees. Based on these results, we found that second-generation Chinese pine seed orchards in Zhengning and Xixian should adopt a grouped, unbalanced, complete, fixed block design and an unbalanced, incomplete, fixed block design, respectively. This study will provide practical references for applying molecular markers to establishing advanced-generation seed orchards.

Effects of Different Ectomycorrhizal Fungal Inoculates on the Growth of Pinus tabulaeformis Seedlings under Greenhouse Conditions

“…Due to its versatility and resiliency, it is considered an important tree species for forest restoration in Northwestern China. Moreover, it provides other important ecosystem functions, including enrichment of headwaters, soil fertility, and water conservation [1,2].…”

Improved genetic distance-based spatial deployment can effectively minimize inbreeding in seed orchard

“…DNA markers can be effectively used to determine the genetic distance and estimate kinship among individuals as well as their inbreeding levels (Vaillancourt et al 1998;Hardy 2003). The molecular marker-based genetic distance estimation among individuals have been used for pedigree reconstruction and paternity testing (Han et al 2017;Huang et al 2018), and it was also used for determining the spatial arrangement of an orchard population but only where the numbers of parents is limited (Yuan et al 2016). Here, we used SSR markers to analyze the genetic distance among 224 clones of Mongolian pine 1st-, 1.5-, and 2nd-generation seed orchards.…”

Asynchronous flowering in clonal seed orchards - An effective strategy for alternative management

“…Seed orchards are the strong link between breeding programs and plantation establishment. They are designed and managed to produce seeds of superior genetic quality compared to those obtained from seed production areas, seed stands or unimproved stands will provide an advance generation of seed orchards by applying molecular markers technique [2]. The optimum goal of a seed orchard is achieved when the orchard population is under an idealized situation.…”