Apple (Malus x domestica Borkh.) is a long-lived woody perennial important to international markets. Development of new apple cultivars historically has been protracted and expensive, largely due to its biology. We believe that locating markers linked to traits of interest and marker-assisted selection (MAS) at the seedling stage could accelerate this process. Quantitative trait locus (QTL) mapping and genome-wide association studies (GWAS) for traits important to the sustainability and longevity of the Canadian apple industry, such as storage disorders, disease resistance, and fruit quality were conducted in three populations. Two QTL associated with the storage disorder soft scald were detected in the parental background of one F1 cross, but were not replicated across years, or when GWAS were conducted in a different population. Apple scab (Venturia ineaqualis [Cke.] Wint.) is a fungal pathogen that plagues growers in wet, humid climates, such as Nova Scotia. Significant genotype-phenotype GWAS associations were detected across seven different chromosomes for apple scab resistance in a germplasm collection of commercial cultivars. In the same population, GWAS also revealed SNPs associated with fruit quality traits, such as apple fruit skin colour and change in firmness during storage. Finally, a large, diverse germplasm collection and GWAS were used to explore flowering time and fruit quality. Significant marker-trait associations were found for flowering time in two years, but no clear candidate genes were identified. Fruit quality studies revealed several significant genotype-phenotype associations, including harvest date, fruit firmness, and acidity. This research will form the foundation of future studies for the development of markers that will assist with the development of new apple cultivars well-suited for Canadian and international markets.

Recent advances in plant genomics and molecular biology have revolutionized our understanding of plant genetics, providing new opportunities for more efficient and controllable plant breeding. Successful techniques require a solid understanding of the underlying molecular biology as well as experience in applied plant breeding. Bridging the gap between developments in biotechnology and its applications in plant improvement, Molecular Plant Breeding provides an integrative overview of issues from basic theories to their applications to crop improvement including molecular marker technology, gene mapping, genetic transformation, quantitative genetics, and breeding methodology.

The basic concept of this book is to examine the use of innovative methods augmenting traditional plant breeding towards the development of new crop varieties under different environmental conditions to achieve sustainable food production. This book consists of two volumes: Volume 1 subtitled Breeding, Biotechnology and Molecular Tools and Volume 2 subtitled Agronomic, Abiotic and Biotic Stress Traits. This is Volume 1 which consists of 21 chapters covering domestication and germplasm utilization, conventional breeding techniques and the role of biotechnology. In addition to various biotechnological applications in plant breeding, it includes functional genomics, mutations and methods of detection, and molecular markers. In vitro techniques and their applications in plant breeding are discussed with an emphasis on embryo rescue, somatic cell hybridization and somaclonal variation. Other chapters cover haploid breeding, transgenics, cryogenics and bioinformatics.

Addressing the pear genome, this book covers the current state of knowledge regarding genetic and genomic resources, breeding approaches and strategies, as well as cutting-edge content on how these tools and resources are being / soon will be utilized to pursue genetic improvement efforts that will combine fruit quality, high productivity, precocious fruit bearing, and long postharvest storage life, along with elevated levels of resistance to various major diseases and insect pests. Throughout, the book also explores potential opportunities and challenges in genomic analysis, sequence assembly, structural features, as well as functional studies that will assist in future genetic improvement efforts for pears. The pear (Pyrus), an important tree fruit crop, is grown worldwide, and has several economically relevant cultivars. In recent years, modern genetic and genomic tools have resulted in the development of a wide variety of valuable resources for the pear. In the past few years, completion of whole genome assemblies of ‘Dangshansuli’, an Asian pear, and ‘Bartlett’, a European pear, have paved the way for new discoveries regarding for example, the pear’s genomic structure, chromosome evolution, and patterns of genetic variation. This wealth of new resources will have a major impact on our knowledge of the pear genome; in turn, these resources and knowledge will have significant impacts on future genetic improvement efforts.

Genetically engineered (GE) crops were first introduced commercially in the 1990s. After two decades of production, some groups and individuals remain critical of the technology based on their concerns about possible adverse effects on human health, the environment, and ethical considerations. At the same time, others are concerned that the technology is not reaching its potential to improve human health and the environment because of stringent regulations and reduced public funding to develop products offering more benefits to society. While the debate about these and other questions related to the genetic engineering techniques of the first 20 years goes on, emerging genetic-engineering technologies are adding new complexities to the conversation. Genetically Engineered Crops builds on previous related Academies reports published between 1987 and 2010 by undertaking a retrospective examination of the purported positive and adverse effects of GE crops and to anticipate what emerging genetic-engineering technologies hold for the future. This report indicates where there are uncertainties about the economic, agronomic, health, safety, or other impacts of GE crops and food, and makes recommendations to fill gaps in safety assessments, increase regulatory clarity, and improve innovations in and access to GE technology.