IV.8 Designation of genes in barley for reaction to Erysiphe graminis (DC) Merat hordei Em. Marchal.
J. G. Moseman. Plant Genetics and Germplasm Institute, U. S. Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705, USA.
Several hundred barley varieties and selections have been reported to be resistant to the pathogen Erysiphe graminis hordei and more than 100 are known to have one or more genes conditioning their resistant reactions. Twenty-eight varieties and selections with the old and new designations for the genes conditioning their resistance reactions are listed in Table 1. These varieties and selections have been submitted to Dr. Tsuchiya to be included in the barley genetic stock collection. Eleven of the varieties and selections are known to have different genes or alleles at or near the Reg1 (Ml-a) locus on chromosome 5. Those eleven different genes are identified by the second number, Reg1a1 to Reg1k11 in the gene designations. When genes are known to be at or near the same locus but it has not been determined if they are different, the second number in the designation for that gene has been omitted.
Other barley varieties and selections known to have specific genes conditioning their resistant reactions to the powdery mildew fungus may be added to the barley genetic stock collection during the next year. I would appreciate being informed when specific genes conditioning resistance to the powdery mildew fungus are identified in other barley varieties or selections.
