title: Genetic diversity among Korean bermudagrass (Cynodon spp.) ecotypes characterized by morphological, cytological and molecular approaches.
abstract: The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.
authors.affiliation: Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185, Korea. gjlee@kaeri.re.kr
authors.forename: Si-Yong
authors.initials: SY
authors.lastname: Kang
authors.forename: Geung-Joo
authors.initials: GJ
authors.lastname: Lee
authors.forename: Ki Byung
authors.initials: KB
authors.lastname: Lim
authors.forename: Hye Jung
authors.initials: HJ
authors.lastname: Lee
authors.forename: In Sook
authors.initials: IS
authors.lastname: Park
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Chung
authors.forename: Jin-Baek
authors.initials: JB
authors.lastname: Kim
authors.forename: Dong Sub
authors.initials: DS
authors.lastname: Kim
authors.forename: Hye Kyung
authors.initials: HK
authors.lastname: Rhee
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D002467:Cell Nucleus / Q000378:metabolism; D032461:Chromosomes, Plant / Q000378:metabolism; D031744:Cynodon / Q000033:anatomy & histology / Q000166:cytology* / Q000235:genetics*; D018744:DNA, Plant / Q000032:analysis; D005434:Flow Cytometry; D014644:Genetic Variation; D005843:Geography; D007723:Korea; D008938:Mitosis; D010802:Phylogeny; D025341:Principal Component Analysis
chemical_list: D018744:DNA, Plant