Development of a molecular marker for the adult plant leaf rust resistance gene Lr35 in wheat

Abstract

The objective of this work was to develop a marker for the adult plant leaf rust resistance gene Lr35. The Lr35 gene was originally introgressed into chromosome 2B from Triticum speltoides, a diploid relative of wheat. A segregating population of 96 F( 2 )plants derived from a cross between the resistant line ThatcherLr35 and the susceptible variety Frisal was analysed. Out of 80 RFLP probes previously mapped on wheat chromosome 2B, 51 detected a polymorphism between the parents of the cross. Three of them were completely linked with the resistance gene Lr35. The co-segregating probe BCD260 was converted into a PCR-based sequence-tagged-site (STS) marker. A set of 48 different breeding lines derived from several European breeding programs was tested with the STS marker. None of these lines has a donor for Lr35 in its pedigree and all of them reacted negatively with the STS marker. As no leaf rust races virulent on Lr35 have been found in different areas of the world, the STS marker for the Lr35 resistance gene is of great value to support the introgression of this gene in combination with other leaf rust (Lr) genes into breeding material by marker-assisted selection.

Mapping of the leaf rust resistance gene Lr38 on wheat chromosome arm 6DL using SSR markers

“…For instance, the cosegregating RFLP marker Lrk10 was converted into a PCRbased sequence-tagged-site (STS) marker for the gene Lr10 (Schachermayr et al 1997) and Naik et al (1998) converted the random ampliWed polymorphic DNA (RAPD) marker OPJ-01 378 into an STS marker for the gene Lr28. Seyfarth et al (1999) also developed an STS marker for the gene Lr35 through cloning and sequencing of a cosegregating RFLP probe and, currently, Urbanovich et al (2006) developed and applied DNA marker assays to select leaf rust resistance at nine loci in wheat.…”

“…The use of PCR-based markers for the identiWcation of leaf rust resistance genes can assist to reduce time, eVorts and expenses for backcross breeding and pyramiding of major resistance genes into wheat cultivars (Naik et al 1998;Gupta et al 1999;Seyfarth et al 1999). For this reason, we believe that the SSR markers linked to Lr38 can facilitate the eVort to reduce the introgression size in future backcrosses.…”

Genetic analysis of rust resistance genes in global wheat cultivars: an overview

“…The combined effects of seedling resistance genes, such as Lr16, Lr47, Lr19, Lr41, Lr21, Lr25 and Lr29, with APR genes, such as Lr34, SV2, Lr46, might explain the highly durable and effective leaf rust control that has been achieved in Argentinean wheat cultivars [45]. The combination of Lr35 with seedling and/or other adultplant leaf rust resistance genes should facilitate more efficient breeding for durable resistance [155]. Genes Lr34, Lr46 and Lr67 provide partial or slow resistance to leaf rust and are considered more durable than seedling resistance genes [173].…”

Fine mapping, physical mapping and development of diagnostic markers for the Rrs2 scald resistance gene in barley

“…However, other possibilities, for example an inversion, could not be excluded. Additionally, suppressed recombination in the vicinity of resistance gene loci which had been introgressed from wild relatives into hexaploid wheat were reported for stem rust resistance gene Sr22 (Paull et al 1994), and leaf rust resistance genes Lr9 (Schachermayr et al 1994), Lr24 (Schachermayr et al 1995), and Lr35 (Seyfarth et al 1999). …”