title: SRAP analysis on genetic relationships of genotypes in the genusMalusMill.
abstract: Thirteen sequence-related amplified polymorphism (SRAP) primers combined with polymerase chain reaction (PCR) were used to evaluate the genetic relationships among 24 genotypes of the genusMalusMill. including Sect.Malus,Baccatus,SorbomalusandChloromeles. Out of 115 surveyed fragments, 107 (93.04%) were polymorphic. Coefficients of genetic similarity ranged from 0.538 to 0.868, with an average value of 0.720 between pairs of materials, which indicated the high degree of polymorphism within this species. Cluster analysis showed that all genotypes were divided into six groups. A dendrogram showed that some of the clustered genotypes were largely congruent for geographical distribution. The species in Sect.Malus,SorbomalusandChloromeleswere separated to a great extent. However, the DNA patterns for some genotype groups did not demonstrate relative agreement in their pedigrees. In Sect.Sorbomalus,M. yunnanesiswas independently separated, whileM. prattiiwere clustered in group III withM. bhutanica,M. platycarpaandM. fuscaclassified into Ser.Kansuenses. Five species originated from the American region were dispersed into two groups within the dendrogram. The conflicts were reflecting their complex genetic backgrounds.
authors.affiliation: College of Forest Resources and Environment, Nanjing Forestry University , Jiangsu , Nanjing , P. R. China.
authors.forename: Rongxue
authors.initials: R
authors.lastname: Xu
authors.affiliation: College of Life Science, Ludong University , Shandong , Yantai , P. R. China.
authors.forename: Dechang
authors.initials: D
authors.lastname: Hu
authors.affiliation: College of Life Science, Ludong University , Shandong , Yantai , P. R. China.
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Chen
authors.affiliation: College of Life Science, Ludong University , Shandong , Yantai , P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.affiliation: College of Life Science, Ludong University , Shandong , Yantai , P. R. China.
authors.forename: Xiaoman
authors.initials: X
authors.lastname: Jiang
authors.affiliation: College of Forest Resources and Environment, Nanjing Forestry University , Jiangsu , Nanjing , P. R. China.
authors.forename: Gengguo
authors.initials: G
authors.lastname: Tang
keywords: Malus Mill.; SRAP; genetic relationship; phylogeny