Genetic Diversity of Paeonia rockii (Flare Tree Peony) Germplasm Accessions Revealed by Phenotypic Traits, EST-SSR Markers and Chloroplast DNA Sequences

Abstract

Research Highlights: This study, based on the first collection of cultivated Paeonia rockii (flare tree peony, FTP) germplasm across the main distribution area by our breeding desires, comprehensively evaluates these accessions by using phenotypic traits, expressed sequence tag (EST)-simple sequence repeat (SSR) markers and chloroplast DNA sequences (cpDNA). The results show that these accessions collected selectively by us can represent the genetic background information of FTP as a germplasm of tree crops. Background and Objectives: FTP has high cultural, ornamental and medicinal value traditionally, as well as recently presenting a significance as an emerging edible oil with high α-linolenic acid contents in the seeds. The objectives of this study are to reveal the characteristics of the genetic diversity of FTP, as well as to provide scientific suggestions for the utilization of tree peony breeding and the conservation of germplasm resource. Materials and Methods: Based on the phenotypic traits, EST-SSR markers and chloroplast DNA sequence variation, we studied the diversity of a newly established population of 282 FTP accessions that were collected and propagated by ourselves in our breeding project in recent years. Results: (1) There was an abundant variation in phenotype of the accessions, and the phenotypic variation was evenly distributed within the population, without significant hierarchical structure, (2) the EST-SSR data showed that these 282 accessions had relatively high genetic diversity, in which a total of 185 alleles were detected in 34 pairs of primers. The 282 accessions were divided into three distinct groups, and (3) the chloroplast DNA sequences (cpDNA) data indicated that these accessions had a higher genetic diversity than the population level and a lower genetic diversity than the species level of wild P. rockii, and the existing spatial genetic structure of these accessions can be divided into two branches. Conclusions: From the results of the three analyses, we found that these accessions can fully reflect the genetic background information of FTP germplasm resources, so their protection and utilization will be of great significance for genetic improvement of woody peonies.

Dissection of Allelic Variation Underlying Floral and Fruit Traits in Flare Tree Peony (Paeonia rockii) Using Association Mapping

“…Then, the two methods were utilized to evaluate population structure and produced coincident consequences. Through STRUCTURE analysis, the 160 accessions were divided into three subgroups, and to a large extent, this was supported by the NJ tree analysis, which was similar to previous reports of three subgroups in FTP ( Wu et al, 2017 ; Guo et al, 2020 ). Furthermore, Yuan et al (2012) revealed that 335 wild P. rockii individuals were mainly divided into three subpopulations, which were strongly linked to the geographical distribution pattern of wild P. rockii .…”

“…Therefore, it was very important to use molecular markers to analyze genetic diversity and population structures. In this study, 81 SSRs detected a total of alleles in 160 accessions, and the N A was 6.09, which was larger than SSRs in individuals (N A = 4.5; Wu et al, 2017) and 34 SSRs in 282 cultivars (N A = 5.441; Guo et al, 2020), but smaller than 12 SSRs in 335 individuals of wild P. rockii (N A = 9.15; Yuan et al, 2012). This suggested that, on the one hand, the SSR primers and plant materials used in this study had comparatively higher allele variation, and on the other hand, the diverse primers and materials used in the studies gave rise to discrepancies.…”

“…A total of 160 accessions (each containing three clones), representing the core germplasm resources of FTP that had been demonstrated and described by Guo et al (2020) , were used in this study. All the samples were originally introduced from Gansu Province in Northwest China, which was the main cultivation area, and had been randomly cultivated in the same nursery field of Beijing Guose Peony Garden in Beijing, China (40°45'N, 115°97'E) for more than 10 years.…”

Paeonol for the Treatment of Atherosclerotic Cardiovascular Disease: A Pharmacological and Mechanistic Overview

“…The cork drop is pink with protruding lenticels while the inner surface is light brown or gray-yellow with a fine longitudinal texture and shiny crystals. It has a special aroma and a slightly bitter taste (18). and triterpenoids, especially phenols (19)(20)(21)(22).…”

Research and Application of Molecular and Phenotypic Data for Tree Biodiversity Evaluation

“…The study by Guo et al [8] was based on the first collection of cultivated Paeonia rockii (flare tree peony, FTP) germplasm, across the main distribution area. Using phenotypic traits, expressed sequence tag (EST)-simple sequence repeat (SSR) markers and chloroplast DNA sequences (cpDNA), the authors showed that the selected accessions could fully reflect the genetic background information of FTP germplasm resources, so their protection and utilization would be of great significance for genetic improvement of woody peonies.…”