The occurrence of Sr31 and Sr36 stem rust resistance genes in wheat cultivars registered in Hungary in the past 25 years

Stem rust along with foliar diseases is a harmful pathogen causing strong yield reduction worldwide. Resistant cultivars provide efficient way for wheat growers to avoid yield losses. In our study, 200 wheat cultivars registered in Hungary in the past twenty five years, were investigated using molecular markers. A significant part of the cultivars carried the 1BL.1RS translocation, the source of Sr31, Lr26, Yr9 and Pm8 genes or the Triticum timopheevi introgression with Sr36 gene. During this period, Sr36 proved to be the strongest and durable stem rust resistance gene in Hungary. Resistance provided by the Sr31 was also effective, although to a less extent than Sr36. The remainder of the resistance genes from 1BL.1RS demonstrated less (Pm8) or no appropriate (Lr26 and Yr9) level of resistance. It seems that the introgression of alien chromosome translocations did not increase the choice of stem rust resistance genes in wheat cultivars registered in Hungary, as the use of efficient resistance genes became very biased. Among the two main wheat breeding programs in Hungary, the spread of Sr31 resistance gene in cultivars of Martonvasar institute (West Hungary) had reached 90% (use of Sr36 was marginal). Conversely, in the Szeged-institute (South-East Hungary) cultivars, Sr36 reached the frequency of 50%, while Sr31 was only exception there. There is an urgent need to incorporate several resistance genes against main diseases into the new wheat cultivars. To accelerate it, marker assisted selection provides new and efficient possibility.