Minimizing Egyptian wheat yield loss to disease through resistance gene enrichment breeding

Ahmed Fawzy Elkot, Brande Wulff

Abstract

Wheat is the most important cereal crop in Egypt where it provides 30% of the population’s calorie intake. More than 1.4 million hectares are farmed to wheat, equivalent to 30% of cultivated land in Egypt. The total annual production, nearly 9 million tons provides just over 50% of the national consumption. The deficit is covered by imports, mainly from Russia and France, rendering the Egyptian economy vulnerable to international currency fluctuations. Narrowing the gap between production and consumption is therefore of high strategic interest. Wheat production in Egypt is constantly threatened by rust and mildew diseases, which have caused heavy yield losses in recent years. These diseases can be genetically controlled by resistance genes in the plant, but when single resistance genes are deployed over large areas they tend to be rapidly overcome by selection for virulent races in the pathogen population. However, lines containing ‘pyramids’ of multiple resistance genes against each pathogen are likely to provide durable disease control. Hence, a key priority of the Egyptian national wheat breeding programme at the Agricultural Research Centre is to develop wheat lines which combine multiple resistance genes against each disease. A new technology developed at the John Innes Centre, UK allows the rapid discovery and sequence identification of functional disease resistance genes by coupling association genetics to resistance gene enrichment sequencing (RenSeq). we used this enabling technology to define the functional resistance gene repertoire against rusts and mildew in a diverse panel of 320 wheat lines.