The influence of eyespot resistance genes on baking quality and yield in wheat

In a backcross programme to introduce resistance genes, the retention of genes other than the resistance gene from the donor parent is possible owing to either chance, the simultaneous transfer of linked genes, incomplete compensation of replaced wheat chromatin, or other crossover segments being incorporated into the wheat genotype. This may cause unwanted characteristics in resistant cultivars. Eyespot in wheat is caused by Pseudocercosporella herpotrichoides (Fron) Deighton. This disease is widely spread throughout the world and can result in severe damage to wheat crops. Genetic control of the disease has been found to be very effective. The aim of this study was to determine the effect of the Pch1 eyespot resistance gene, backcrossed 8-10 times into South African wheat cultivars SST66 and Palmiet, on baking quality and yield in the absence of the disease. The presence of the gene had a detrimental effect on thousand-kernel mass in two SST66 lines and on yield in one Palmiet line, but there were no detrimental effects on any measured quality characteristics. The presence of the gene will thus protect the plant from the disease without having a negative effect on baking quality. (C) 2002 Society of Chemical Industry.