Differential suppression of stripe rust resistance in synthetic wheat hexaploids derived from Triticum turgidum subsp. dicoccoides and Aegilops squarrosa

• Published in: Phytopathology Vol. 85; no. 4; pp. 425 - 429
• Main Authors: Kema, G.H.J. (IPO-DLO, Wageningen, The Netherlands.), Lange, W, Silfhout, C.H. van
• Format: Journal Article Conference Proceeding
• Language: English
• Published: St. Paul, MN American Phytopathological Society 1995
• Subjects: AEGILOPS SQUARROSA; Agronomy. Soil science and plant productions; AMELIORATION DES PLANTES; Biological and medical sciences; EXPRESION GENICA; EXPRESSION DES GENES; FITOMEJORAMIENTO; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; GENOTIPOS; GENOTYPE; Instituut voor Plantenziektenkundig Onderzoek; Pest resistance; Plant pathogens; PODER PATOGENO; POUVOIR PATHOGENE; PUCCINIA STRIIFORMIS; Research Institute for Plant Protection; RESISTANCE AUX MALADIES; RESISTENCIA A LA ENFERMEDAD; ROUILLE; ROYA; SELECCION; SELECTION; TRITICUM TURGIDUM; Varietal selection. Specialized plant breeding, plant breeding aims; Aegilops squarrosa; Puccinia striiformis; Monocotyledones; Genetic inheritance; Plant pathogen; Hexaploidy; Triticum dicoccoides; Basidiomycetes; Host agent relation; Fungus resistance; Fungi; Breeding line; Gramineae; Angiospermae; F1 hybrid; F2 hybrid; Wild plant; Spermatophyta; Thallophyta
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/phyto-85-425

The expression of resistance to stripe rust of wheat, conditioned by four Aegilops squarrosa (DD, 2n = 14) and 11 Triticum turgidum subsp. dicoccoides (AABB, 2n = 28) accessions, was studied by testing 22 synthetic hexaploids (AABBDD, 2n = 42) with five stripe rust races in the seedling stage and two races in the adult plant stage. Resistance in one or both parents was frequently suppressed in the synthetic hexaploids, indicating the presence of suppressor genes on the AB and D genomes. Specificity was apparent because the putative suppressor genes affected the expression of specific resistance genes, although not with all races nor in all growth stages. The results and data from F1 and F2 populations derived from crosses between two synthetic hexaploids with the same T. t. dicoccoides parent but with different A. squarrosa parents revealed that several recessively inherited suppressor genes on the D genome seemed to be involved. A possible mechanism explaining these results and the variable mode of action of suppressors are discussed