Molecular Breeding to Improve Forages for Use in Animal and Biofuel Production Systems

Abstract

Forage cultivars with positive impacts on animal production are currently being released using traditional plant breeding approaches. Molecular breeding is a relatively new term that describes the use of genomic and transgenic biotechnologies in conjunction with traditional breeding. Traits currently under investigation via these biotechnologies include herbicide tolerance, drought tolerance, resistance to disease and insect pests, tolerance to acid, aluminum toxic and/or saline soils, tolerance to cold or freezing injury, expression of plant genes controlling nodulation and nitrogen fixation, increasing nutritional quality via down regulation of lignin genes, flowering control, and reducing pasture bloat via incorporation of genes to express condensed tannins. Molecular breeding approaches are expensive, and in the case of transgenics, controversial, requiring much planning and even partnerships or consortia with others to defray cost, and overcome a “valley of death” for commercialization due to patent and regulatory issues. Trait incorporation via molecular breeding being conducted by the Consortium for Alfalfa Improvement is discussed as an example of this type of research approach. The future of molecular breeding in forage crops is bright, but is tied to funding, and in the case of transgenics, also lies in the hands of regulatory agencies and their ability to establish a fair process to evaluate real versus perceived risks. Finally, the use of forages as cellulosic biofuel crops offers new molecular breeding opportunities, especially for value added traits such as enhanced biomass and fermentation efficiency. The main criteria for any biofuel crops are high yields achieved with low input costs in an environmentally friendly manner. By this definition, many high yielding, currently grown, perennial forages are good candidates as biofuel crops especially if they can be delivered to a biorefinery as cheaply as possible.