Blumeria graminis

Blue-X (Iraqi incapacitating agent. Thought to be BZ or a derivative.) Blumeria graminis B. melitensis Bn-Stoff... 

The Qol fungicides bind to the Qo site of cytochrome b and inhibit the electron flow at the bcl enzyme complex of the respiratory chain in the mitochondria. They are widely used because of their broad-spectrum activity [4], However, a few years after the commercial use of Qols resistant isolates of Blumeria graminis f. sp. tritici were detected in some regions of Northern Germany [5], Since then, resistant isolates have been fotmd in a range of pathogens [4]. 

Interestingly, the cleistothecial powdery mildew Blumeria graminis (fig. 3 Erysiphales) clusters with Sclerotinia sclerotiorum [319]. Additional complete 18S rDNA sequences of powdery mildew fungi are necessary to clarify the phylogenetic relationship between Erisyphales and Leotiales. It is, however, remarkable that many representatives of the Leotiales have asci with thick-walled apices [Oberwinkler, pers. commun.]. 

Besides the intrinsic properties of each resistance mechanism, the economic impact of Qol resistance on the Qol market is also governed by the availability of alternative fungicidal modes of action for disease control and resistance management in each crop. For example, the early and rapid development of resistance of cereal powdery mildew (Blumeria graminis) in European wheat and barley production from 1998 on had a remarkably low impact on Qol consumption. The broad disease spectrum controlled by Qols and the availability of several other modes of action for the control of powdery mildews in cereals such as DMIs, amines, cyprodinil, quinoxyfen, and metrafenone resulted in a nearly unchanged use frequency of Qols in European cereal production. 

Aminopyrimidines 2 Cucumber and cereal powdery mildews Sphaerothecafuliginea and Blumeria graminis Medium... 

Amlino-pyrimidines 5 Grape Botrytis cinerea apple Venturia inaequalis-, wheat Blumeria graminis and Ocidimacula spp. Low... 

Quinoxyfen 4 Wheat and barley Blumeria graminis Low to medium... 

Erysiphe (Blumeria) graminis f.sp. tritici 3 Mycosphaerella graminicola 19... 

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