ARS | Publication request: Breeding New Varieties to Reduce Pre-Harvest Mycotoxin Contamination

Submitted to: World Mycotoxin Forum, the Third Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 6, 2006
Publication Date: N/A

Technical Abstract: Plant breeding has played a major role in the advancement of human civilization. The domestication and continued improvement of plant species allowed more people to be fed by a significantly smaller portion of the population thereby allowing other individuals to focus on improving other facets of civilization. Even with the advent of new breeding strategies and methodologies, maize breeders traditionally discard moldy ears and use visually healthy seed for future breeding. Although humans have been consuming grains for thousands of years, the importance of mold and mycotoxin contamination has only recently been recognized as a significant health risk. As more countries implement regulations to limit mold and mycotoxin contamination in their food and feed, breeders face increasing pressure to successfully identify, develop, and commercialize resistant germplasm. To date, most mycotoxin resistance breeding strategies have focused on germplasm selection as well as development and validation of screening methods. The integration of genetic and molecular methods to elucidate gene-to-phenotype relationships has significantly improved germplasm breeding; unfortunately disease and mycotoxin screening methods have not advanced as rapidly due to inherent variation in the screening systems thereby impeding the development of commercially acceptable resistant germplasm. The impact of abiotic stresses is a major contributor to this variation due to their effect on both plant and pathogen growth and development. Additionally, the stable performance of commercial products from modern plant breeding programs depends on a decreasing number of elite genetic combinations, and any undetected stress sensitivity may lead to yield reductions and mycotoxin contamination across a significant area. Recent plant breeding strategies to develop germplasm that is resistant to multiple stresses represent a unique opportunity to also characterize fungal and mycotoxin resistance. Historically, selection for abiotic stress resistance relied on performance evaluations averaged over multiple locations each with similar environments. Due to the stochastic nature of weather-associated stresses and the limited number of similar environments, plant breeders are relying on managed stress environments which allow stringent control of the environment, timing, and intensity of imposed stresses. This paper will discuss the utility of managed stress environments to breed new varieties resistant to pre-harvest mycotoxin contamination.