Breeding and variety development strategies for Cercospora resistance in sugar beet

Depending on the geographical region where the disease occurs, different de mands are made on varieties resistant to Cercospora beticola in respect of the level of resistance, the existence of additional other resistances, per formance in the absence of attack, and level of sugar content. Whereas in t he heavily affected regions of northern Italy highly Cercospora-resistant v arieties are cultivated, in Germany varieties are required which, while med ium resistant, are also able to compete in the absence of the disease. In E urope, Cercospora-resistant varieties should also be resistant to rhizomani a. In the United States, Cercospora-resistant varieties are also resistant to the causal organism of root rot Aphanomyces cochlioides and exhibit an e xtremely high sugar content. In bleeding, the combination of resistances ca n be achieved by combining different resistances through the parents in the production of hybrids. In the production of its American high-quality Cerc ospora-resistant varieties, KWS employs extremely sugar-rich tetraploid pol len contributors.