No abstract

Background. Stem rust of wheat, caused by the biotrophic fungus Puccinia graminis Pers. f. sp. tritici Eriks. et Henn., is a dangerous disease that afflicts serious economic damage to the cultivation of durum wheat.Materials and methods. Cultivars and promising materials developed at the Spring Durum Wheat Breeding Laboratory, Omsk Agrarian Scientific Center (OASC), lines obtained under the CIMMYT and KASIB programs, and accessions from the VIR collection were the objects of research. Field experiments, phenological observations, and assessment of stem rust resistance were carried out from 1990 through 2019 in the OASC experimental fields using conventional methods. Resistance to the Ug99 race was evaluated under natural infection pressure at the Kenya Agricultural and Livestock Research Organization (KALRO).Results. Promising source material was identified and included in the Laboratory’s breeding program. The ways were shown to develop stable cultivars of spring durum wheat for the environments of Western Siberia. A strategy was proposed for the selection of genotypes in hybrid combinations of spring durum wheat: it would include early selection (starting from F2 ) for disease resistance with simultaneous screening for quantitative traits and pasta-making qualities. The description and advantages of cv. ‘Omsky korall’, submitted to the State Variety Trials in 2018, are presented. This cultivar combines high yield, adaptability, resistance to the local population and the Ug99 race of the stem rust pathogen, and excellent pasta-making qualities.Conclusion. As a result of these studies under heavy stem rust pressure in Western Siberia, all breeding nurseries obtained source material resistant to the Omsk population of P. graminis. The released cultivars ‘Omskaya yantarnaya’ and ‘Omsky izumrud’ demonstrate resistance to the Omsk population of the stem rust causative agent.

Common wheat is the main grain crop in Russia. Leaf rust caused by the fungus Puccinia triticina Erikss. regularly affects crops and leads to economic damage. To protect wheat, the use of genes of related cereals is promising. The effect of Lr-genes introduced from Aegilops speltoides Tausch was estimated in Western Siberia and the Southern Urals in 2013-2018. Plant damage was assessed in the field, and the frequency of virulent clones in P. triticina population was detected. The Lr28 and LrSp genes provided plant immunity, and virulent clones were absent in the population. An outbreak of reproduction of a clone virulent to Lr47 was first recorded in the steppe zone of the Omsk region, bordering with Northern Kazakhstan in 2013, with subsequent migration to the East, North and West. Virulence to Lr47 disappeared in the Southern Urals in 2018, but is annually detected in Western Siberia with a low frequency. The tendency to overcome the adult Lr35 gene and the low efficiency of Lr36 in Western Siberia and the Southern Urals was noted. The breeding of wheat varieties with Ae. speltoides genes and their cultivation should take into account the pathogen variability and migration.

No abstract

No abstract