title: Genetic diversity in  tetraploid switchgrass revealed by AFLP marker polymorphisms.
abstract: Switchgrass  (Panicum virgatum) is a perennial warm-season grass native to North  America that has been identified as a dedicated cellulosic biofuel crop. We  quantified genetic diversity in tetraploid switchgrass germplasm collected at  Oklahoma State University and characterized genetic relatedness among the  collections from distinct regions. Fifty-six tetraploid accessions, including  seven upland and 49 lowland genotypes from throughout the US, were examined.  The amplified fragment length polymorphism (AFLP) procedure was utilized to  generate DNA profiling patterns that were scored visually. Sixteen selective  AFLP primer combinations were used to amplify 452 polymorphic bands. The  accessions' genetic similarity coefficients, UPGMA (unweighted pair-group  method with arithmetic averaging) cluster analysis and principle coordinate  analysis, were performed. The upland and lowland accessions clustered according  to ecotypes, with one exception (TN104). Genetic similarity coefficients among  the accessions ranged from 0.73 to 0.95. Analysis of molecular variance (AMOVA)  was performed, showing significant differences between the upland and lowland  genotypes. The trnL marker confirmed that TN104 was a lowland genotype,  but the trnL marker identification of upland and lowland genotypes was  not consistent with the AFLP analysis in two germplasms (Miami and AR4).
authors.affiliation: Department of Plant and Soil Sciences, Oklahoma State University, OK, USA.
authors.forename: J
authors.initials: J
authors.lastname: Todd
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Wu
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Samuels
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis / Q000379:methods*; D001483:Base Sequence; D056804:Biofuels; D001947:Breeding; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D060146:Ecotype; D004587:Electrophoresis, Agar Gel; D005819:Genetic Markers; D005838:Genotype; D008969:Molecular Sequence Data; D009825:Oklahoma; D008897:Panicum / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D025341:Principal Component Analysis; D057891:Tetraploidy
chemical_list: D056804:Biofuels; D017931:DNA Primers; D005819:Genetic Markers