Finding the perfect potato: using functional genomics to improve disease resistance and tuber quality traits

Abstract

One of the best known plant disease outbreaks of all time was the Irish potato famine of 1845 to 1847 when the late blight pathogen, Phytophthora infestens, devastated the potato crop and caused more than one million deaths in Ireland. Potatoes are still plagued by disease but luckily most countries do not depend on potato as much as they did in Ireland in the 1800s. Producing disease-free potatoes, however, has come at a huge cost. To combat major diseases, such as late blight and common scab, 64 × 106 kg of pesticides are sprayed on potato fields each year. The costs associated with these measures are not only financial; environmental costs, although less easy to quantify, are significant and include negative impacts on natural ecosystems and the contamination of groundwater, lakes, and rivers. Our search for the “perfect” potato, i.e., one that has good processing qualities and disease resistance, has gained new momentum with the emergence of genomic technologies. Through functional genomics we will gain a better understanding of the genes responsible for tuber quality traits and those responsible for disease resistance. With a collection of desirable genes in mind, we can again use genomics as a diagnostic tool to search for these genes in the wide variety of potatoes around the world and to follow their transfer by classical breeding. This paper describes a research program currently underway in Canada that uses functional genomics to improve the potato.