Genetic diversity analysis based on sequence-related amplified polymorphism (SRAP) reveals the genetic background of Xinan tree peony group cultivars from different geographical provenances

Abstract

The Xinan tree peony cultivar group, one of four Chinese peony cultivar groups, is distributed sparsely throughout Southwest China. This study aimed to characterize its genetic diversity and its genetic relationships with other peony groups. A total of 96 specimens from seven groups of different geographical provenances were collected and their genetic similarity was analyzed based on sequence-related amplified polymorphism molecular markers. Twenty primer pairs were selected to detect DNA polymorphisms. A total of 868 bands were generated with an average of 43.4 bands per primer pair and 98.39% polymorphic ratio. The genetic similarity coefficient varied from 0.5081 to 0.9173. The closest phylogenetic relationship was found between hybrids 2 and 3 of Paeonia rockii, while the farthest genetic relationship was between P. lutea and P. suffruticosa ‘Bangningzi’. Among the 20 Xinan samples the genetic similarity coefficient ranged from 0.6351 to 0.8710, revealing slight genetic variation. The 96 cultivars clustered into five branches at the genetic similarity coefficient of 0.6419. The results revealed that the Xinan group has a closer relationship with Japanese, French and American groups. Additionally, these results show that the phylogenetic relationships of different tree peony germplasms correspond to their origins and are primarily related with flower color.