title: Genetic diversity of  sea-island cotton (Gossypium barbadense) revealed by mapped SSRs.
abstract: In  order to evaluate the genetic diversity of sea-island cotton (Gossypium  barbadense), 237 commonly mapped SSR markers covering the cotton genome  were used to genotype 56 sea-island cotton accessions. A total of 218  polymorphic primer pairs (91.98%) amplified 361 loci, with a mean of 1.66 loci.  Polymorphism information content values of the SSR primers ranged from 0.035 to  0.862, with a mean of 0.320. The highest mean polymorphism information content  value for the SSR motifs was from a compound motif (0.402), and for the  chromosomes it was Chr10 (0.589); the highest ratio of polymorphic primers in  Xinjiang accessions was from Chr21 (83.33%). Genetic diversity was high in  Xinjiang accessions. AMOVA showed that variation was 8 and 92% among  populations and within populations, respectively. The 56 sea-island accessions  were divided into three groups in the UPGMA dendrogram: Xinhai5 was in the  first group; accessions from Xinjiang, except the five main ones, were in the  second group, and the other 34 accessions were in the third group. Accessions  from the former Soviet Union and Xinjiang main accessions were closely related.  Both PCA and UPGMA confirmed that Xinhai5 was distinct from the other  accessions, and accessions from Xinjiang were in an independent group. Given  the differences between principal components analysis and UPGMA results, it is  necessary to combine molecular markers and pedigree information so that genetic  diversity can be objectively analyzed.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, Hubei, China.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Wang
authors.forename: C H
authors.initials: CH
authors.lastname: Feng
authors.forename: Z X
authors.initials: ZX
authors.lastname: Lin
authors.forename: X L
authors.initials: XL
authors.lastname: Zhang
mesh_terms: D002874:Chromosome Mapping / Q000379:methods*; D032461:Chromosomes, Plant / Q000235:genetics; D014644:Genetic Variation; D005843:Geography; D003368:Gossypium / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D059372:Nucleotide Motifs / Q000235:genetics; D009792:Oceans and Seas; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis