Analysis of genetic resistance to powdery mildew disease in sugar beet

Development of resistant variety to powdery mildew (PM) is necessary. Therefore, during past years some of the sugar beet genotypes were screened to this disease in Kermanshah. One of the genotypes named 14442 showed resistance to PM disease. This genotype with two male sterile lines (MS261 and MS231) was used to determine the number of genes responsible for resistance to disease. Crosses between 14442, MS261 and MS231 were done and segregating generations were evaluated. Based on results, F2 plants in both crosses (14442*MS261 and 14442*MS231) could be divided in two phenotypic classes with ratio of 3:1. In back crosses two phenotypic classes with ratio of 1:1 were obtained. These results showed that PM disease was controlled with a single dominant gene.