Phenotypic and Start Codon Targeted (SCoT) polymorphism reveals the genetic variation of Crataegus bretschneideri C. K. Schneid. and related species in China

Abstract Crataegus bretschnesideri C. K. Schneid. originated in Northeast China, it has excellent characteristics of cold resistance and early maturity. However, the taxonomic status of C. bretschnesideri has been controversial due to the intra-specific hybridization and apomixes. Comparative assessment of phenotypic and molecular evaluations used to explore genetic diversity of C. bretschneideri and relative species. Qualitative and quantitative traits of C. bretschneideri and relative species were evaluated. Genetic diversity and population structure of several Crataegus species were analyzed by thirteen reported and five newly designed SCoT markers. Leaf traits of Crataegus had a higher Shannon-wiener index than fruit and flower traits; Fruit contained diverse traits among seven Crataegus species by principal component analysis. SCoT markers amplified 148 polymorphic bands with 94.87% polymorphic loci. Crataegus individuals clustered into five clades, and C. bretschneideri had a closer relationship with C. pinnatifida Bge. and C. hupehensis Sarg.. Population structure suggested that investigated the mixed gene pool appeared in C. bretschneideri. There had variation among Crataegus species, and part of the C. bretschneideri individuals may be a hybrid origin compared to the phenotypic and molecular evaluations. Newly designed SCoT markers were practical for Crataegus diversity analyses.