Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 22, 2008
Publication Date: April 30, 2008
Citation: Rector, B.G. 2008. Molecular biology approaches to control of intractable weeds: New strategies and complements to existing biological practices. Plant Science, vol. 175, pp. 437-448. Interpretive Summary: Classical biological control is often attempted as a "last resort" to control weed invasions that have escaped other means of control. However, when classical biological control is ineffective or impossible, new approaches are necessary to achieve efficacious, economical weed control. Advances in molecular biology knowledge and technology may provide such means. This paper reviews non-chemical weed control strategies proposed to address invasive weed challenges with the help of molecular biology tools and techniques.
Technical Abstract: Molecular genetic tools and concepts are in relentless and continuous development, affecting every field of biology. Biological control of weeds, an applied science with over a century of history, is no exception. This field has been dominated from the beginning by its foundation concept, classical biological control (CBC), which seeks to reunite invasive weeds with their native natural enemies in order to establish an ecological equilibrium in the invaded range that reduces weed populations to sub-economic levels. However, CBC is not applicable to every weed problem and is not always successful in controlling those to which it applies. In these cases molecular biology may be able to supplement or replace CBC in the effort to check invasive weed populations. In theory, any biological control strategy could be improved through molecular biology, whether it involves improvement to the biological control agent (e.g. increased lethality, improved specificity, ability to work in concert with other pest management tactics), improvement to an affected crop (e.g. enhanced allelopathy or competition for resources), or increased knowledge regarding the evolution of the target and its natural enemies, which can affect the search for and selection of CBC agents. Molecular genetic tools can also suggest novel strategies that would not be possible in their absence, as well as allow weed biological control scientists to borrow molecular solutions from virtually any field of biology, including biological control of other pests (e.g. fungi, arthropods, or vertebrates) and other fields without obvious or traditional connections to weed biological control. This paper will review concepts of classical and molecular biological control of weeds, as well as propose novel strategies. Social issues surrounding weed biological control in general and CBC and molecular biology in particular, such as risk assessment, government regulation, and perception vs. reality, will also be discussed.