Resistance to eyespot of wheat, caused by Tapesia yallundae, derived from Thinopyrum intermedium homoeologous group 4 chromosome

• DOI: 10.1007/s00122-005-0025-0
• Publication Date: 2005-08-01T12:45:40Z
• Authors: H. J. Li; M. Arterburn; S. S. Jones; T. D. Murray
• Keywords: 0301 basic medicine; 2. Zero hunger; 03 medical and health sciences; Ascomycota; Chromosome Mapping; Chromosomes, Plant; Genome, Plant; Immunity, Innate; In Situ Hybridization; Triticum; Plant Diseases

Thinopyrum intermedium was identified previously as resistant to Tapesia yallundae, cause of eyespot of wheat. Using GUS-transformed isolates of T. yallundae as inoculum, we determined that wheat lines carrying Th. intermedium chromosome 4 Ai#2 or the short arm of chromosome 4 Ai#2 were as resistant to the pathogen as the eyespot-resistant wheat- Th. ponticum chromosome substitution line SS 767 (PI 611939) and winter wheat cultivar Madsen, which carries gene Pch 1 for eyespot resistance. Chromosome 4 E from Th. elongatum and chromosome 4 J from Th. bessarabicum did not confer resistance to T. yallundae. Genome-specific PCR primers confirmed the presence of Thinopyrum chromatin in these wheat- Thinopyrum lines. Genomic in situ hybridization using an St genomic probe from Pseudoroegneria strigosa demonstrated that chromosome 4 Ai#2 belongs to the J(s) genome of Thinopyrum. The eyespot resistance in the wheat- Th. intermedium lines is thus controlled by the short arm of this J(s) chromosome. This is the first report of resistance to T. yallundae controlled by a J(s) genome chromosome of Th. intermedium.