RESISTANCE OF DASYPYRUM-VILLOSUM TO THE CEREAL EYESPOT PATHOGENS, TAPESIA-YALLUNDAE AND TAPESIA-ACUFORMIS

Resistance to T. yallundae and T. acuformis was studied in addition li nes of D. villosum chromosomes to Chinese Spring wheat and in five D. villosum accessions. In order to investigate the resistance of D. vill osum chromosomes to the two eyespot pathogens, inoculated seedlings we re scored by visual estimates of disease severity 10 weeks after inocu lation. In addition, DNA was isolated from these plants and the fungal DNAs of both species were quantified by competitive PCR. Visual asses sment showed D. villosum to be resistant (to both T. yallundae and ir: acuformis) compared to Chinese Spring. The level of pathogen DNA was also generally lower in D. villosum accessions than in Chinese Spring. The resistance to T. yallundae was determined by factor(s) on chromos omes 1V, 2V, 3V(?) and 4V. In contrast resistance to I acuformis was n ot found on 4V but on chromosome 1V, 2V, 3V(?) and to a lesser extent 5V. This work indicates that in D. villosum the genetic basis of resis tance to the two pathogens differs.