Download or read book Genetic and Molecular Mapping Studies on a Population Derived from Vitis Vinifera X Muscadinia Rotundifolia and Genetic Diversity of Wild Muscadinia Rotundifolia written by Brady Phillip Smith and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The wine grape, Vitis vinifera [L.], is believed to have evolved through selection of wild progenitors in the Middle East and Europe over the last 10,000 years. The current domesticated form is a worldwide economically important commodity, utilized for wine, juice, fresh and dried fruit, and food products. The North American grape, Muscadinia rotundifolia [Michx.] Small, is primarily grown in its native habitat of the southeastern United States. Muscadinia rotundifolia is naturally resistant to many of the pests and pathogens that hinder V. vinifera production. Genetic mapping of 123 V. vinifera x M. rotundifolia (VR) F1 hybrids from four related populations was conducted to assemble the first reported haploid map of M. rotundifolia. This is the first step in generating markers associated with traits of interest for markers-assisted breeding. A total of 56 simple sequence repeat (SSR) and 73 amplified fragment length polymorphism (AFLP) markers were used to assemble a consensus haploid map of M. rotundifolia which covered 20 linkage groups. The cumulative map length was 1270.8 cM, with an average distance of 10.1 cM between markers. The traits of sex determination and rooting were assigned position on the linkage map. The amplification patterns of SSR markers in M. rotundifolia compared to Vitis spp. suggests that there are both highly conserved and highly diverged genomic regions. Genetic diversity of 24 wild sub-populations of M. rotundifolia was measured and compared with wild accessions collected in the 19th century. A total of 278 wild accession of M. rotundifolia were genotyped at 15 SSR loci for population structure analysis. The total mean genetic diversity (observed heterozygosity of 0.485) was primarily due to differences among individuals within sub populations (83.3%). The mean genetic diversity is lower than values reported for wild forms of V. vinifera (0.597), and is most likely attributed to divergence between the genera at the loci examined. Advances in rootstock breeding were accomplished by identifying three partially fertile F1 hybrids of North American species of Vitis and M. rotundifolia. These hybrids were used to generate the next generation of rootstocks that may provide superior protection against grapevine pathogens.