Principles of Plant Genetics and Breeding

Section 5
Tools in plant breeding
Chapter 10 Sexual hybridization and wide crosses in plant breeding
Chapter 11 Tissue culture and the breeding of clonally propagated plants
Chapter 12 Mutagenesis in plant breeding
Chapter 13 Polyploidy in plant breeding
Chapter 14 Biotechnology in plant breeding
Chapter 15 Issues in the application of biotechnology in plant breeding
This section discusses the application of the principles and concepts of plant genetics and breeding to the
development of new cultivars. Methods of plant genetic manipulation have changed over the years as new
knowledge and technology have become available. The first generation technology for plant manipulation was
non-invasive, requiring artificial crossing to accomplish gene mixing to create new genotypes. This method is
restrictive in that only sexually compatible plants can be improved this way. Second generation technologies of
tissue culture, mutagenesis, and chromosome manipulation allowed more intrusive plant genetic manipulation,
targeting cells or the genetic material relatively more directly. The first and second generation technologies
are generally classified as conventional plant breeding tools. In this section, the student will learn the scientific
basis and application of hybridization, tissue culture, induced mutations, and ploidy in the genetic manipulation
of plants. In addition, the cutting edge technology of genetic engineering that enables researchers to
directly manipulate plants at the molecular level will be discussed. Because this powerful technology allows scientists
to transfer DNA across natural biological barriers, its developments and applications are often mired in
controversy. Consequently, the issues of risk and regulation of biotechnology are also discussed in this section.