title: Association of RGA-SSCP markers  with resistance to downy mildew and anthracnose in  grapevines.
abstract: Downy  mildew (Plasmopara viticola) and anthracnose (Sphaceloma ampelinum)  are two major diseases that severely affect most grapevine (Vitis vinifera)  cultivars grown commercially in Thailand. Progress of conventional breeding  programs of grapevine for improved resistance to these diseases can be speeded  up by selection of molecular markers associated with resistance traits. We  evaluated the association between 13 resistance gene analog (RGA)-single-strand  conformation polymorphism (SSCP) markers with resistance to downy mildew and  anthracnose in 71 segregating progenies of seven cross combinations between  susceptible cultivars and resistant lines. F(1) hybrids from  each cross were assessed for resistance to downy mildew and anthracnose  (isolates Nk4-1 and Rc2-1) under laboratory conditions. Association of  resistance traits with RGA-SSCP markers was evaluated using simple linear  regression analysis. Three RGA-SSCP markers were found to be significantly correlated  with anthracnose resistance, whereas significant correlation with downy mildew  resistance was observed for only one RGA-SSCP marker. These results demonstrate  the usefulness of RGA-SSCP markers. Four candidate markers with significant  associations to resistance to these two major diseases of grapevine were  identified. However, these putative associations between markers and resistance  need to be verified with larger segregating populations before they can be used  for marker-assisted selection.
authors.affiliation: Suranaree University of Technology, Nakhon Ratchasima, Thailand. piyada@sut.ac.th
authors.forename: P A
authors.initials: PA
authors.lastname: Tantasawat
authors.forename: O
authors.initials: O
authors.lastname: Poolsawat
authors.forename: T
authors.initials: T
authors.lastname: Prajongjai
authors.forename: W
authors.initials: W
authors.lastname: Chaowiset
authors.forename: A
authors.initials: A
authors.lastname: Tharapreuksapong
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D003433:Crosses, Genetic; D060467:Disease Resistance / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D017343:Genes, Plant / Q000235:genetics; D056726:Genetic Association Studies; D005819:Genetic Markers; D006824:Hybridization, Genetic; D016014:Linear Models; D044742:Peronospora / Q000502:physiology*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018807:Polymorphism, Single-Stranded Conformational / Q000235:genetics*; D027843:Vitis / Q000235:genetics* / Q000382:microbiology
chemical_list: D005819:Genetic Markers