Modelling environmentally suitable areas for the potential introduction and cultivation of the emerging oil crop Paeonia ostii in China.

Paeonia ostii is a traditional ornamental and medicinal species that has attracted considerable interest for its high oil value. To facilitate the effective and rational cultivation and application of P. ostii in China, it is necessary to determine its potential spatial habitat distribution and environmental requirements. Using high-resolution environmental data for current and future climate scenarios, the potential suitable area and climatic requirements of P. ostii were modelled. Among the 11 environmental variables investigated, growing degree days, precipitation of the wettest month, mean temperature of the coldest quarter, global UV-B radiation, annual precipitation, and soil pH played major roles in determining the suitability of a habitat for the cultivation of P. ostii. Under the current environmental conditions in China, a total area of 20.31 × 105 km2 is suitable for growing P. ostii, accounting for 21.16% of the country's total land area. Under the two future climate scenario/year combinations (i.e., representative concentration pathways [RCPs], RCP2.6 and RCP8.5 in 2050), this species would increase its suitable area at high latitudes while decrease at low latitudes. These results present valuable information and a theoretical reference point for identifying the suitable cultivation areas of P. ostii.

Genetic structure of the tree peony (Paeonia rockii) and the Qinling Mountains as a geographic barrier driving the fragmentation of a large population.

BACKGROUND: Tree peonies are great ornamental plants associated with a rich ethnobotanical history in Chinese culture and have recently been used as an evolutionary model. The Qinling Mountains represent a significant geographic barrier in Asia, dividing mainland China into northern (temperate) and southern (semi-tropical) regions; however, their flora has not been well analyzed. In this study, the genetic differentiation and genetic structure of Paeonia rockii and the role of the Qinling Mountains as a barrier that has driven intraspecific fragmentation were evaluated using 14 microsatellite markers. METHODOLOGY/PRINCIPAL FINDINGS: Twenty wild populations were sampled from the distributional range of P. rockii. Significant population differentiation was suggested (F(ST) value of 0.302). Moderate genetic diversity at the population level (H(S) of 0.516) and high population diversity at the species level (H(T) of 0.749) were detected. Significant excess homozygosity (F(IS) of 0.076) and recent population bottlenecks were detected in three populations. Bayesian clusters, population genetic trees and principal coordinate analysis all classified the P. rockii populations into three genetic groups and one admixed Wenxian population. An isolation-by-distance model for P. rockii was suggested by Mantel tests (r = 0.6074, P<0.001) and supported by AMOVA (P<0.001), revealing a significant molecular variance among the groups (11.32%) and their populations (21.22%). These data support the five geographic boundaries surrounding the Qinling Mountains and adjacent areas that were detected with Monmonier's maximum-difference algorithm. CONCLUSIONS/SIGNIFICANCE: Our data suggest that the current genetic structure of P. rockii has resulted from the fragmentation of a formerly continuously distributed large population following the restriction of gene flow between populations of this species by the Qinling Mountains. This study provides a fundamental genetic profile for the conservation and responsible exploitation of the extant germplasm of this species and for improving the genetic basis for breeding its cultivars.

Microsatellite markers for the Chinese herbaceous peony Paeonia lactiflora (Paeoniaceae).

PREMISE OF THE STUDY: Microsatellite (simple sequence repeat, SSR) primers were developed for the Chinese peony, P. lactiflora, to investigate the diversity within Chinese peony germplasm resources. METHODS AND RESULTS: Using an SSR-enriched genomic library, a set of 10 unique polymorphic genomic SSRs was developed and characterized. The primers amplified 61 alleles in all 10 loci, including di-, tri-, and tetranucleotide repeats. The primers were also effective for P. veitchii and P. obovata. CONCLUSIONS: The new primers will be useful for genetic research of the Chinese peony and extend the repertoire of SSR markers available to study the herbaceous taxa in Paeonia.