Sources of Resistance to Common Bunt (Tilletia foetida and T. caries) in Durum Wheat

Screening of durum wheat germplasm for resistance to common bunt (Tilletia foetida and T. caries) resulted in the identification of 26 resistant genotypes. The screening was made using nine common bunt isolates from the West Asia and North Africa (WANA) region. In one isolate the two pathogens were represented in ratio of 1:1, whereas eight isolates contained only T. foetida. The correlation, principal components and clustering analyses grouped the genotypes into three clusters., Cluster one comparised genotypes close to Senatore (S.) Cappelli and Haurani, the latter is a landrace from Syria. Cluster three comprised advanced genotypes containing resistance genes from Mindum, a Turkish landrace. Results indicated that donor sources of resistance appear to be related to the three major sources mentioned. Cultivar S. Cappelli is considered resistant since it has been grown by farmers on a large scale for many years and remained resistant to common bunt throughout 7 years of testing. This resistance is assumed to be of a durable type. The isolates were also grouped into three clusters representing different ecological areas and the wheat types from which the isolates originated. We infer that the different clusters reflect the presence of three pathotype groups of the pathogens.