Molecular Detection of Resistance to Biotic Stress Conditions in Spring Bread Wheat Cultivars

Abstract

Biotic stress conditions are the most serious obstacle in bread wheat cultivation resulting in yield reduction and safety problems (toxin production) for consumers. For this reason, identification of resistant cultivars and their respective genes is a main prerequisite in most breeding programs. Into this study and in order to exploit the benefits of molecular technology, 9 Hellenic and 93 Ukrainian bread wheat cultivars were analyzed to determine the responsible alleles for some important diseases in wheat. Among the Hellenic cultivars, carriers of resistance-associated alleles of the Lr34/Yr18/Pm38/Sr57/Bdv1 (a rare gene among the European bread wheat cultivars), Tsn1, Tsc2, and TDF_076_2D genes were identified. Four of the studied Hellenic cultivars carry the 1BL.1RS wheat-rye chromosome translocation of the ‘Kavkaz’ type proved to be resistant to the stem rust and especially to the dangerous Sicilian race TTTTF due mainly to the presence of the Sr31 gene. Among the Ukrainian cultivars, the toxin A insensitivity allele of the Tsn1 gene is predominant. Οf the nine Ukrainian spring cultivars containing wheat-rye translocations, seven were found to possess the 1BL.1RS and two the ‘Amigo’-type 1AL.1RS translocation. The previous two cultivars carry the gene Sr1RSAmigo conferring resistance to dangerous stem rust Ug99 biotypes. One cultivar (‘Vyshyvanka’) was found to carry a 1BL.1RS translocation distinct from 1BL.1RS of the ‘Kavkaz’ type and may carry novel rye disease resistance genes. The results of the examined germplasm regarding disease resistance gene alleles could be helpful for breeders who are looking for sources of disease resistance genes.