RESUMO
Downy mildew (Plasmopara viticola) and anthracnose (Sphaceloma ampelinum) are two of the major diseases of most grapevine (Vitis vinifera L.) cultivars grown in Thailand. Therefore, breeding grapevines for improved downy mildew and anthracnose resistance is crucial. Factorial crosses were made between three downy mildew and/or anthracnose resistant lines ('NY88.0517.01', 'NY65.0550.04', and 'NY65.0551.05'; male parents) and two or three susceptible cultivars of V. vinifera ('Black Queen', 'Carolina Black Rose', and/or 'Italia'; female parents). F1 hybrid seedlings were evaluated for downy mildew and anthracnose resistance using a detached/excised leaf assay. For both diseases, the general combining ability (GCA) variance among male parents was significant, while the variance of GCA among females and the specific combining ability (SCA) variance were not significant, indicating the prevalence of additive over non-additive gene actions. The estimated narrow sense heritabilities of downy mildew and anthracnose resistance were 55.6 and 79.2%, respectively, suggesting that downy mildew/anthracnose resistance gene(s) were highly heritable. The 'Carolina Black Rose x NY65.0550.04' cross combination is recommended for future use.
Assuntos
Resistência à Doença/genética , Peronospora/imunologia , Doenças das Plantas/imunologia , Saccharomycetales/imunologia , Vitis/genética , Cruzamento , Genes de Plantas , Imunidade Inata , Infecções/imunologia , Micoses/imunologia , Vitis/imunologiaRESUMO
Genetic maps of Vitis (2n = 38) have been constructed from an interspecific hybrid population of 58 seedlings of the cross 'Horizon' ('Seyval' x 'Schuyler') x Illinois 547-1 (V. cinerea B9 x V. rupestris B38). The maps were initially constructed based on 277 RAPD (random amplified polymorphic DNA) markers using a double-pseudotestcross strategy. Subsequently, 25 microsatellites, 4 CAPS (cleaved amplified polymorphic sequence), and 12 AFLP (amplified fragment length polymorphism) markers were added to the maps. Another 120 markers, mostly those segregating 3:1, were also assigned but not positioned on the linkage groups in the two maps. The 'Horizon' map consisted of 153 markers covering 1199 cM, with an average map distance of 7.6 cM between markers. The Illinois 547-1 map had 179 markers covering 1470 cM, with an average map distance of 8.1 cM. There were 20 linkage groups in each map, one more than the basic number of chromosomes in grapes. Ten linkage groups in each map were identified as homologous using 16 microsatellite and 2 CAPS markers polymorphic in both parents. A single locus controlling sex in grapes mapped close to a microsatellite marker. These maps provide enough coverage of the genome for QTL (quantitative trait loci) analysis and as a starting point for positional gene cloning in grapes.