Sources of resistance to brown rust pathogen and their use in the development of soft wheat varieties

Abstract

Purpose. To select alien genes among those identified and described in special literature that are resistant to brown rust and introgressed in Triticum aestivum L. sources, determine their origin and prospects of use in breeding practice.

Results. Soft spring wheat as the basic cereal crop belongs to the group of plants cultivated in controlled conditions for a long time. During the vegetation period it can be adversely affected by pathogens, so the search for sources of resistance to them is a priority task of breeding. Brown rust is one of the most widespread and harmful diseases of wheat. It causes significant yield losses and deterioration of grain quality. The population of the pathogen Puccinia recondita is highly adaptive. High variability of the fungus virulence leads to the accumulation of pathogens which can destroy genes of wheat resistance. The most environmentally safe method to control disease is creating resistant varieties. The effectiveness of breeding for resistance to brown rust can be increased by using different Lr-genes of resistance. Now in wheat genome and its relatives more than 90 (Lr) genes of resistance to brown rust pathogen are identified and characterized for chromosomal localization and effectiveness. It was found that almost all genes of resistance to brown rust to be effective in Ukraine except Lr10 and Lr23 are alien transferred to Triticum aestivum from other species: Aegilops speltoides – genes Lr28, Lr35, Lr36, Lr47, Lr51, Lr66; Aegilops tauschii – Lr1, Lr21, Lr22a, Lr32, Lr39, Lr42; Triticum timopheevii – Lr18 and Lr50; Thinopyrum elongatum – Lr19, Lr29, Lr24; Secale cereale – Lr25, Lr26 and Lr45; Aegilops umbellulata – Lr9, Lr76; Triticum spelled – Lr44, Lr65, Lr71; Triticum dicoccoides – Lr53, Lr 64; Aegilops triuncilis – Lr58, LrTr; Tr. timopheevii spp. viticulosum – LrTt1; Aegilops ventricosa – Lr37; Aegilops kotschyi – Lr54; Elymus trachycaulis – Lr55; Aegilops sharonensis – Lr56; Aegilops geniculate – Lr57; Aegi­lops peregrine – Lr59; Triticum turgidum – Lr61; Aegilops neglecta – Lr62; Triticum monococcum – Lr63.

Conclusions. The use of cultivars and wildlife species of wheat relatives in crossing will allow to obtain breeding material to be inhomogenous as for resistance to brown rust pathogen.