Genetic mapping and marker assisted selection (MAS) is considered as one of the major tools in genetic improvement of crop plants in this genomics era. This book describes basics in linkage mapping, step-by-step procedure to perform MAS, achievements made so far in different crops, and limitations and prospects of MAS in plant breeding. It summarizes all this in a simple but comprehensive mode using suitable examples so as to explain the concept and its historical developments. To summarize, this book describes technologies for identification of genes of interest through genetic mapping, recaps the major applications of MAS to plant breeding; lists examples in which MAS is being applied to various breeding programs, and emphasizes the various difficulties that limit the application of MAS in plant breeding, providing possible solutions to overcome these difficulties, and finally tries to illustrate the future prospects. This book would be a valuable guide to the under-graduates and post-graduates of agricultural universities and institutes that are interested and/or involved in genetic improvement of crop plants using modern tools. Bibliography listed in this book constitutes two parts: literature cited and further reading. Literature cited contains references cited in the text and further information on the given concept/technique can be obtained from these references. Further reading provides a list of suggested readings for in-depth coverage of the topics.

Linkage maps and quantitative trait loci (QTL) analysis have become essential tools for the positional cloning of agronomically important genes and for marker-assisted breeding. In this study, two North American grape species, Vitis rupestris and Vitis riparia, and their 294 F1 progeny were used to construct parental linkage maps and to perform QTL analysis for downy mildew resistance. Single nucleotide polymorphism (SNP) discovery was accomplished using genotyping-by-sequencing (GBS) and resulted in 348,888 SNPs. Of these, 11,063 informative SNP markers (3.17% of the original SNP dataset) were derived after filtering for various quality parameters and missing data. A two-way pseudo-testcross strategy was followed for map construction using JOINMAP®5.0. The 1,115 and 1,177 significant markers (threshold LOD ≥ 14) for V. riparia and V. rupestris were grouped into 19 linkage groups covering 1657.4 and 1401.3 centimorgan (cM) of genetic distances with an average marker interval of 1.49 and 1.19 cM, respectively. Maps were validated by pinpointing a single significant QTL which determined maleness on chromosome 2 in the genetic background of the V. riparia male parent. Phenotype data for leaf downy mildew resistance were collected with both in vitro and naturally inoculated leaves of 86 and 136 F1 progeny, respectively. With both methods, QTL analysis for reduced leaf area coverage by mildew lead to a significant peak on chromosome 10 in V. rupestris explaining 15-45% of the phenotypic variance. For in vitro inoculation, a significant QTL was detected for reduced sporangiophore density on chromosome 8 of V. riparia, explaining 15% of the variance. These are the first SNP-based linkage maps of these native North American grape species. The maps are expected to serve as a resource for breeding modern varieties for environment-friendly grape cultivation.

Grapevine is a highly valuable crop worldwide, both from a cultural as well as a commercial point of view. One of its major advantages is that it is well adapted to scarce water conditions. The main object of grapevine breeding is to develop varieties that are resistant to pathogens and at the same time well-adapted to a changing environment. Since

This book fully integrates the conventional and biotechnological approaches to fruit crop breeding. Individual chapters are written on a wide variety of species covering all the major fruit crops in one volume. For each crop, there is a discussion of their taxonomy and evolution, history of improvement, crossing techniques, evaluation methods, and heritability of major traits and germplasm resources. Also discussed are the most recent advances in genetic mapping and QTL (quantitative trait loci) analysis, marker assisted breeding, gene cloning, gene expression analysis, regeneration and transformation. Patenting and licensing issues are also covered.

The grape and wine industry relies heavily on sulfur and sulfur containing compounds to control the fungal disease powdery mildew (PM). Sulfur dioxide induces large-scale transcriptomic modification in the Eurasian grape species Vitis vinifera with little to no phytotoxicity. However, genetic factors contributing to sulfur sensitivity, characterized by vegetative necrosis and defoliation, remain undefined in North American grape species and their commercial hybrids. A mapping population, consisting of 147 F1 genotypes, was created by crossing V. aestivalis-derived ‘Norton’ and V. vinifera ‘Cabernet Sauvignon’ to identify the genetic basis for sulfur sensitivity in North American wine grapes. Clonally propagated F1 genotypes were fumigated with sulfur burners under greenhouse conditions. Association and linkage mapping were conducted using single nucleotide polymorphisms (SNPs) and simple sequence repeat (SSR) markers, respectively. A major quantitative trait loci (QTL) for sulfur sensitivity was detected on linkage group 14 (LOD=15). Identification of this QTL will allow future grape breeding programs produce commercially suitable hybrids, which do not display sulfur sensitivity, via marker assisted selection (MAS).

A comprehensive description and assessment of the use of marker-assisted selection for increasing the rate of genetic gain in crops, livestock, forestry and fish, including the related policy, FAO's tradition of dealing with issues of importance to agricultural and economic development in a multidisciplinary and cross-sectoral manner.