The international breeding strategy for the incorporation of resistance in bread wheat against the soil borne pathogens (Dryland Root Rot and cyst and lesion Cereal Nematodes) using conventional and molecular tools

Abstract

Soil borne pathogens (SBPs) including the Dryland Root Rots and Cereal Nematodes are causing economic yield loss in many parts of the world where cereals dominate the cropping system and sub-optimal growing conditions or cultural practices are common. One of the most effective control measures of these SBPs is the use of host resistance, whereby the inoculum level of these pathogens can be reduced to below economically damaging thresholds. CIMMYT International in collaboration with The Turkish Ministry of Agriculture and Rural Affairs have established an International field and laboratory screening program for identifying spring and winter wheat accessions with resistance to SBPs. Several screening protocols for assessing resistance to both cereal root rots and nematodes have been modified and optimized. Known resistance sources to SBPs from other regions of the world have been tested against Turkish isolates of SBPs and several of these have been shown to be effective in the region. In addition new sources of resistance with genetic variability have been identified against the prevalent SBPs. These diverse genes for resistance are being pyramided into both spring and winter bread wheat backgrounds using both conventional and molecular tools where feasible.