Mapping a leaf rust resistance gene LrOft in durum wheat Ofanto and its suppressor SuLrOft in common wheat

Xiangxi Zhuansun; Junna Sun; Nannan Liu; Shengnan Zhang; Huifang Wang; Zhaorong Hu; Jun Ma; Qixin Sun; Chaojie Xie

doi:10.3389/fpls.2023.1108565

Mapping a leaf rust resistance gene LrOft in durum wheat Ofanto and its suppressor SuLrOft in common wheat

Front Plant Sci. 2023 Apr 21:14:1108565. doi: 10.3389/fpls.2023.1108565. eCollection 2023.

Authors

Xiangxi Zhuansun^{1

2}, Junna Sun^{1

2}, Nannan Liu^{1

2}, Shengnan Zhang^{1

2}, Huifang Wang^{1

2}, Zhaorong Hu^{1

2}, Jun Ma^{1

2}, Qixin Sun^{1

2}, Chaojie Xie^{1

2}

Affiliations

¹ Key Laboratory of Crop Heterosis and Utilization (Ministry of Education), China Agricultural University, Beijing, China.
² Beijing Key Laboratory of Crop Genetic Improvement, Beijing, China.

Abstract

Epidemics of leaf rust (caused by the fungal pathogen Puccinia triticina Erikss., Pt) raise concerns regarding sustainability of wheat production. Deployment of resistant cultivars is the most effective and economic strategy for combating this disease. Ofanto is a durum wheat cultivar that exhibits high resistance to Pt race PHT throughout its entire growing period. In the present study, we identified a leaf rust resistance gene in Ofanto and temporarily designated it as LrOft. LrOft was mapped to a 2.5 cM genetic interval in chromosome arm 6BL between Indel markers 6B6941 and 6B50L24. During introgression of LrOft from Ofanto to common wheat it was observed that F₁ plants of Ofanto crossed with Shi4185 exhibited leaf rust resistance whereas the F₁ of Ofanto crossed with ND4503 was susceptible. In order to map the presumed suppressor locus, a Shi4185/ND4503//Ofanto three-way pentaploid population was generated and SuLrOft was mapped on chromosome arm 2AS. SuLrOft was mapped within a 2.6 cM genetic interval flanked by 2AS50L14 and 2AS50L6. Fine mapping using 2,268 plants of the three-way cross narrowed the suppressor locus to a 68.2-kbp physical interval according to IWGSC RefSeq v1.1. Sequence analysis of genes in the physical interval revealed that TraesCS2A02G110800 encoding an RPP-13-like protein with an NB-ARC domain was a potential candidate for SuLrOft.

Keywords: NB-ARC; durum wheat; fine mapping; leaf rust resistance; resistance suppressor.

Grants and funding

This work was supported by the National Natural Science Foundation of China (32171971 and 31872865).