Cytogenetic and molecular identification of novel wheat- Elymus sibiricus addition lines with resistance to leaf rust and the presence of leaf pubescence trait

Ivan I Motsnyi; Oleksii V Halaiev; Tetiana G Alіeksіeіeva; Galyna O Chebotar; Sabina V Chebotar; Alexander Betekhtin; Robert Hasterok; Rita Armonienė; Mahbubjon Rahmatov

doi:10.3389/fpls.2024.1482211

Cytogenetic and molecular identification of novel wheat- Elymus sibiricus addition lines with resistance to leaf rust and the presence of leaf pubescence trait

Front Plant Sci. 2024 Nov 12:15:1482211. doi: 10.3389/fpls.2024.1482211. eCollection 2024.

Authors

Ivan I Motsnyi¹, Oleksii V Halaiev², Tetiana G Alіeksіeіeva², Galyna O Chebotar², Sabina V Chebotar^{1

2}, Alexander Betekhtin³, Robert Hasterok³, Rita Armonienė⁴, Mahbubjon Rahmatov⁵

Affiliations

¹ Department of General and Molecular Genetics, Plant Breeding and Genetics Institute - National Center of Seed and Cultivar Investigation, Odesa, Ukraine.
² Department of Molecular Biology, Biochemistry and Genetics, Odesa I.I. Mechnikov National University, Odesa, Ukraine.
³ Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice, Poland.
⁴ Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry, Akademija, Lithuania.
⁵ Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden.

Abstract

Introduction: Emerging new races of leaf rust (Puccinia triticina Eriks) are threatening global wheat (Triticum aestivum L.) production. Identifying additional resistance genes from all available gene pools is crucial to expanding wheat resistance to these virulent leaf rust races. Siberian wild rye (Elymus sibiricus L.) possesses numerous beneficial traits that can be valuable in wheat improvement. Three new wheat-E. sibiricus addition lines, O27-2 (BC₈), O27-3 (BC₁₂) and O193-3 (BC₁₂), were developed through a backcrossing scheme in this study, using leaf rust field evaluations, molecular marker assays and cytogenetic analysis.

Methods: These three lines were derived from progeny of the bread wheat cultivar 'Obriy' (2n = 6x = 42, AABBDD) and partial octoploid amphiploid wheat-E. sibiricus (2n = 8x = 56, AABBDDS^tS^t).

Results and discussion: The lines (O27-2, O27-3 and O193-3) demonstrated strong specific leaf pubescence (hairiness) and resistance at the adult stage to a local population of leaf rust races. The response to leaf rust in these three lines significantly differed from that of the Lr24 gene, providing evidence for a distinct resistance mechanism associated with the 3S^t chromosome. This study is the first to report the transfer of an E. sibiricus chromosome into wheat that confers leaf rust resistance. Molecular marker analysis and genomic in situ hybridization confirmed that lines O27-2, O27-3 and O193-3 each possess one pair of E. sibiricus 3S^t chromosomes. The resistance gene was determined to be on the additional alien chromosome in these lines. Molecular markers (Xwmc221, Lr29F18, Sr24/Lr24) confirmed that the lines O27-2, O27-3, and O193-3 each contain a pair of E. sibiricus 3S^t chromosomes carrying leaf rust resistance genes. These findings demonstrate that the E. sibiricus 3S^t chromosome carries the leaf rust resistance gene and that the O27-2, O27-3, and O193-3 lines can serve as novel germplasm sources for introducing this resistance into wheat breeding programs. This study contributes to broadening the genetic diversity of resistance genes available for combating leaf rust in wheat.

Keywords: Triticum aestivum; alien introgression; genomic in situ hybridization; leaf hairiness; molecular markers; resistance genes; wild relatives.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. We acknowledge financial support from the Swedish Institute through the "Academic Collaboration in the Baltic Sea Region" funding program for the project "Portfolio of Technology Transfer for Acceleration and Improvement of Wheat Breeding Activities in Ukraine, 01132-2022" and from FORMAS (2018-01029) for Mahbubjon Rahmatov. We also thank the Plant Breeding and Genetics Institute - National Center of Seed and Cultivar Investigation, and Research Excellence Initiative of the University of Silesia in Katowice for supporting this research. We thank Dr. R. Franke, Institute of Breeding Research, Quedlinburg, Germany, for providing a wheat-E. sibiricus introgression line.