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

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

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1108565

DOI=10.3389/fpls.2023.1108565

ISSN=1664-462X

ABSTRACT=<p>Epidemics of leaf rust (caused by the fungal pathogen <italic>Puccinia triticina</italic> Erikss., <italic>Pt</italic>) 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 <italic>Pt</italic> 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 <italic>LrOft</italic>. <italic>LrOft</italic> was mapped to a 2.5 cM genetic interval in chromosome arm 6BL between Indel markers <italic>6B6941</italic> and <italic>6B50L24</italic>. During introgression of <italic>LrOft</italic> from Ofanto to common wheat it was observed that F<sub>1</sub> plants of Ofanto crossed with Shi4185 exhibited leaf rust resistance whereas the F<sub>1</sub> 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 <italic>SuLrOft</italic> was mapped on chromosome arm 2AS. <italic>SuLrOft</italic> was mapped within a 2.6 cM genetic interval flanked by <italic>2AS50L14</italic> and <italic>2AS50L6</italic>. 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 <italic>TraesCS2A02G110800</italic> encoding an RPP-13-like protein with an NB-ARC domain was a potential candidate for <italic>SuLrOft</italic>.</p>