Identification and Monosomic Analysis of Tan Spot Resistance Genes in Synthetic Wheat Lines (Triticum turgidum L. x Aegilops tauschii Coss.)

• Published in: Crop science Vol. 46; no. 3; pp. 1212 - 1217
• Main Authors: Tadesse, W, Hsam, S.L.K, Wenzel, G, Zeller, F.J
• Format: Journal Article
• Language: English
• Published: Madison Crop Science Society of America 01.05.2006; American Society of Agronomy
• Subjects: Aegilops tauschii; Crop diseases; Crop residues; Cultivars; Disease; disease resistance; dominance (genetics); dominant genes; Drechslera; durum wheat; fungal diseases of plants; Genes; Genetic aspects; genetic resistance; Genetics; genotype; Genotypes; Hybrids; intergeneric hybridization; leaf spotting; Plant genetics; plant pathogenic fungi; Plant resistance; Pyrenophora tritici-repentis; recessive genes; strains; synthetic populations; Triticum aestivum; Triticum turgidum; Triticum turgidum subsp. durum; virulence; Wheat; United States
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci2005.10-0396

Tan spot, caused by the fungus Pyrenophora tritici-repentis (Died.) Drechs. (Ptr), anamorph Drechslera tritici-repentis (Died.) Shoem., is becoming a major yield limiting leaf disease of both durum (Triticum turgidum L. var durum) and common wheat (Triticum aestivum L.) worldwide. In this study, differential isolates and varieties were developed, and using the most virulent isolate, ASC1b, we screened about 100 synthetic wheat genotypes against the disease. Two (2%) and 20 (20.4%) of the genotypes were found to be immune and highly resistant, respectively. Monosomic analyses of the F2 hybrids (crosses of the highly resistant accessions (XX41, XX45) and the moderately resistant accession XX110 with the monosomic lines (D-genome) of the wheat cultivar Chinese Spring have revealed that the resistance genes are located on chromosome 3D. The gene in lines XX41 and XX110 showed a recessive monogenic inheritance, whereas the gene in line XX45 exhibited a dominant mode of inheritance. The recessive genes from XX41 and XX110 are tentatively named tsn3 and tsn-syn1, respectively, and the dominant gene from XX45 is named as Tsn-syn2.