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 CONVENTIONALAND MOLECULAR TOOLS

摘要

Soil borne pathogens (SBPs) including the Dryland Root Rots and Cereal Nematode'sare causing economic yield loss in many parts of the world where cereals dominate thecropping 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 TurkishMinistry of Agriculture and Rural Affairs have established an International field andlaboratory screening program for identifying spring and winter wheat accessions withresistance to SBPs. Several screening protocols for assessing resistance to both cerealroot rots and nematodes have been modified and optimized. Known resistance sourcesto SBPs from other regions of the world have been tested against Turkish isolates ofSBPs and several of these have been shown to be effective in the region. In addition newsources of resistance with genetic variability have been identified against the prevalentSBPs. These diverse genes for resistance are being pyramided into both spring andwinter bread wheat backgrounds using both conventional and molecular tools wherefeasible.