Development and characterization of wheat lines carrying stem rust resistance gene Sr43 derived from Thinopyrum ponticum

Abstract

Wheat lines carrying Ug99-effective stem rust resistance gene Sr43 on shortened alien chromosome segments were produced using chromosome engineering, and molecular markers linked to Sr43 were identified for marker-assisted selection. Stem rust resistance gene Sr43, transferred into common wheat (Triticum aestivum) from Thinopyrum ponticum, is an effective gene against stem rust Ug99 races. However, this gene has not been used in wheat breeding because it is located on a large Th. ponticum 7el(2) chromosome segment, which also harbors genes for undesirable traits. The objective of this study was to eliminate excessive Th. ponticum chromatin surrounding Sr43 to make it usable in wheat breeding. The two original translocation lines KS10-2 and KS24-1 carrying Sr43 were first analyzed using simple sequence repeat (SSR) markers and florescent genomic in situ hybridization. Six SSR markers located on wheat chromosome arm 7DL were identified to be associated with the Th. ponticum chromatin in KS10-2 and KS24-1. The results confirmed that KS24-1 is a 7DS·7el(2)L Robertsonian translocation as previously reported. However, KS10-2, which was previously designated as a 7el(2)S·7el(2)L-7DL translocation, was identified as a 7DS-7el(2)S·7el(2)L translocation. To reduce the Th. ponticum chromatin carrying Sr43, a BC(2)F(1) population (Chinese Spring//Chinese Spring ph1bph1b*2/KS10-2) containing ph1b-induced homoeologous recombinants was developed, tested with stem rust, and genotyped with the six SSR markers identified above. Two new wheat lines (RWG33 and RWG34) carrying Sr43 on shortened alien chromosome segments (about 17.5 and 13.7 % of the translocation chromosomes, respectively) were obtained, and two molecular markers linked to Sr43 in these lines were identified. The new wheat lines with Sr43 and the closely linked markers provide new resources for improving resistance to Ug99 and other races of stem rust in wheat.

Harnessing Genetic Diversity of Wild Gene Pools to Enhance Wheat Crop Production and Sustainability: Challenges and Opportunities

“…By genetic (molecular markers) and physical (e.g., FISH or GISH) mapping, introgressions of minimal size still containing the target gene(s) can be selected, and these in the largest majority of cases exert the best overall performance in a breeding perspective. By exploiting high-resolution tools, this goal could be achieved in several instances, both in bread and also durum wheat (see several chapters in [11] and references therein; see also [15][16][17][18][19][20]). As to the latter species, successful examples not only include the transfer of genes for resistance to diseases [14,22,23] and abiotic stresses [24], but also grain quality [14,[25][26][27][28] and yield-related traits [29,30].…”

Genetic mapping of resistance to Diuraphis noxia (Kurdjumov) biotype 2 in wheat (Triticum aestivum L.) accession CI2401

“…Simple sequence repeats (SSRs) are useful for MAS in wheat because of their ease of use and relatively low cost (Peng et al 2009;Plaschke et al 1995;Röder et al 1995). Although high throughput genotyping is now available for wheat (Akhunov et al 2009;Berard et al 2009;Poland et al 2012), SSRs continue to be used, particularly for mapping single genes in defined chromosome locations (Huang et al 2014;Niu et al 2014).…”

A Novel Wheat-<b><i>Dasypyrum breviaristatum </i></b>Substitution Line with Stripe Rust Resistance

“…Wild relatives of wheat provide a vast pool of genes for disease resistance and improved quality [Niu et al, 2011[Niu et al, , 2014. The genus Dasypyrum (or Haynaldia ) consists of 2 species: Dasypyrum villosum and D. breviaristatum.…”