| Ornamental peony refer to a Perennial flower with ornamental values belong to sect. Paeonia, Paeonia L., Paeoniaceae. It is not only our famous traditional flower in China but also occupies an important place in world flower market. With rich germplasm resources, long history of cultivation and wide coverage, they formed three distinctive groups around the world, they are the Chinese Peony Cultivar Group, the European Peony Cultivar Group and the Hybrid Peony Cultivar Group according to the different provenances, respectively. Especially peony in the Hybrid Peony Cultivar Group possesses the significant characteristics of bright color, unique flower type, vigorous growth and strong resistance, which will gradually become the new trend of ornamental peony breeding. Though Paeonia L. have various colors, abundant flower types, well adaptability and wide landscape application, Chinese are often limited to the Chinese peony group and have few understanding of western cultivarsin the European peony group and the hybrid peony group. As a result, these peonies with excellent characteristics have little application in China which will significantly restrict the breeding process of new cultivars. This experiment starts from the development of microsatellite markers with introduced and collected new ornamental germplasms of Paeonia L. from Europe and America regions by our group these years, and explores the genetic diversity of89new cultivars of Euramerican peonies and part of important parental ancestors. Nevertheless, the experiment also constructs the DNA fingerprint. The main research achievements are as follows:1. Microsatellite enrichment libraries has constructed by magnetic beads methods using diploid cultivar ’Charlie’s White’.82Microsatellite loci are obtained by selecting193positive clones from253for sequencing, of which50are desighed primers. Polymorphism of50primers are screened and PCR system is optimized, the results show that15primers are polymorphism (30%) and they can all amplify the clear band.2. Study the genetic diversity of89materials in Paeonia L. using the development of15polymorphism. The results show that89materials can be well amplified.145alleles are obtained from15primers,140(96.6%) alleles of which are polymorphism, with an average of9.3alleles, effecive alleles varies from1.569to5.723, with an average of3.795. PIC value ranges from0.362to0.825with an average of0.678. The maximum of Shannon information index is2.194, the minimum is1.082. Genetic similarity coefficient among89materials ranges from0.35to0.98, the clustering and principal component analysis of89materials are constructed based on UPGMA (Unweighted Pair Group Method With Arithmetic Mean). The clustering and principal component analysis can basically separate these cultivars but differ in the classification of cultivar group. The clustering can more reflect the genetic relationships between materials than principal component analysis. Above all, SSR markers can show plenty diversity information.3. According to PIC value and Shannon information index of15primers, select10characteristic primers for the construction of fingerprint of61cultivars from Europe and America. As a result,61materials can be separated by these characteristic primers. Besides conventional diploid types which have one band, two bands, these new Paeonia cultivars have abundant ploidies which even arise three and four bands. The fingerprint can lay a theoretical basis for new cultivar and ploidy identification of herbaceous Paeonia L. |
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