Date of Graduation

Fall 2014

Degree

Master of Science in Plant Science (Agriculture)

Department

College of Agriculture

Committee Chair

Chin-Feng Hwang

Abstract

The Vitis aestivalis-derived ‘Norton' is a commercial red grape cultivar that can be grown in regions where V. vinifera is difficult to grow, due to high disease pressure and cold temperatures in winter and spring. However, Norton is difficult to propagate from dormant cuttings and is sensitive to sulfur. Molecular techniques may improve breeding for rooting ability and sulfur tolerance capacity in Norton hybrids. The objectives of this study were to: (1) identify interspecific hybrids of Norton and V. vinifera (Pinot Noir, Syrah, and Merlot) and Vitis interspecific hybrid ‘Vignoles' using microsatellite markers; (2) construct a haploid linkage map of V. vinifera ‘Cabernet Sauvignon'; and (3) localize quantitative trait loci (QTLs) governing the rooting ability from dormant cuttings and sulfur tolerance in Cabernet Sauvignon. A high percentage of hybrids (70 - 92%) were obtained in all crosses except Norton x Merlot (17%), which demonstrate the reliability of microsatellite markers for Norton-based interspecific hybrid identification. A complete haploid map of Cabernet Sauvignon covering 1590.8cM was constructed by genotyping 183 F1 progenies of Norton and Cabernet Sauvignon at 272 microsatellite loci. QTLs were detected by non-parametric Kruskal-Wallis test and interval mapping methods. A QTL governing root length was obtained in linkage group 18 that explained 15.9% of the total phenotypic variation. Similarly, QTL governing sulfur tolerance was obtained in linkage group 7 explaining 19.3% of the total phenotypic variation. This result revealed the genomic regions controlling rooting ability and sulfur sensitivity of grapevines, which represents the first step towards development of marker-assisted selection of these traits.

Keywords

Norton, Cabernet Sauvignon, hybrids, microsatellite markers, linkage map, QTLs, dormant cuttings, rooting ability, sulfur sensitivity

Subject Categories

Plant Sciences

Copyright

© Pragya Adhikari

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