Societal Costs of Late Blight in Potato and Prospects of Durable Resistance Through Cisgenic Modification

Abstract

In the European Union almost 6 Mha of potatoes are grown representing a value of close to €6,000,000,000. Late blight caused by Phytophthora infestans causes annual losses (costs of control and damage) estimated at more than €1,000,000,000. Chemical control is under pressure as late blight becomes increasingly aggressive and there is societal resistance against the use of environmentally unfriendly chemicals. Breeding programmes have not been able to markedly increase the level of resistance of current potato varieties. New scientific approaches may yield genetically modified marker-free potato varieties (either trans-and/or cisgenic, the latter signifying the use of indigenous resistance genes) as improved variants of currently used varieties showing far greater levels of resistance. There are strong scientific investments needed to develop such improved varieties but these varieties will have great economic and environmental impact. Here we present an approach, based on (cisgenic) resistance genes that will enhance the impact. It consists of five themes: the detection of R-genes in the wild potato gene pool and their function related to the various aspects in the infection route and reproduction of the late blight causing pathogen; cloning of natural R-genes and transforming cassettes of single or multiple (cisgenic) R-genes into existing varieties with proven adaptation to improve their value for consumers; selection of true to the wild type and resistant genotypes with similar qualities as the original variety; spatial and temporal resistance management research of late blight of the cisgenic genetically modified (GM) varieties that contain different cassettes of R-genes to avoid breaking of resistance and reduce build- the different nature and possible biological improvement and legislative repercussions of cisgenic GM-crops in comparison with transgenic GM-crops. It is important to realize that the present EU Directive 2001/18/EC on GM crops does not make a difference between trans-and cisgenes. These rules were developed when only transgenic GM plants were around. We present a case arguing for an updating and refinement of these rules in order to place cisgenic GM-crops in another class of GMplants as has been done in the past with (induced) mutation breeding and the use of protoplast fusion between crossable species.

Can Precision Agriculture Increase the Profitability and Sustainability of the Production of Potatoes and Olives?

“…It is grown on ca. 20% of the arable land, with a total production of 7.5 million Mg y −1 and a farm-level value of € 800 million [49]. We focus on four precision agriculture operations in potatoes, namely (i) variable rate application of soil herbicides, (ii) fungicides to control late blight, (iii) sidedress N, and (iv) potato haulm killing (PHK) herbicides.…”

Evaluation of PCR markers for Phytophthora infestans mating type determination

“…This pathogen causes a disease named late blight and is able to completely devastate plants within a week. Therefore the average costs of yield losses and chemical protection against late blight are high and calculated at over 6 billion USD worldwide (Haverkort et al 2008). P. infestans is a hemibiotrophic organism, which can reproduce asexually (forming sporangia).…”

Evolution and Management of the Irish Potato Famine Pathogen Phytophthora Infestans in Canada and the United States

“…The pathogen also infects tomato (Solanum lycopersicon L.) and other crop, weedy, and ornamental members of the Solanaceae (Platt 1999). Although worldwide crop losses have more recently been averted through disease management strategies and preventative fungicide treatments, economic losses are still estimated at several billion dollars per annum (Haverkort et al 2008).…”