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ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Biotechnology
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1416078
This article is part of the Research Topic From Classical Breeding to Modern Biotechnological Advancement in Horticultural Crops - Trait Improvement and Stress Resilience, Volume II View all 10 articles

Solanum pimpinellifolium exhibits complex genetic resistance to Pseudomonas syringae pv. tomato

Provisionally accepted
Jana A. Hassan Jana A. Hassan 1Nathan Diplock Nathan Diplock 1Ilea J. Chau-Ly Ilea J. Chau-Ly 1Jamie Calma Jamie Calma 1Elizabeth Boville Elizabeth Boville 1Steven Yee Steven Yee 1Taylor M. Harris Taylor M. Harris 1Jennifer D. Lewis Jennifer D. Lewis 1,2*
  • 1 Department of Plant & Microbial Biology, College of Natural Resources, University of California, Berkeley, Berkeley, California, United States
  • 2 Plant Gene Expression Center, Agricultural Research Service (USDA), Albany, United States

The final, formatted version of the article will be published soon.

    Pseudomonas syringae pv. tomato (Pst) is the causal agent of bacterial speck disease in tomatoes. The Pto/Prf gene cluster from Solanum pimpinellifolium was introgressed into several modern tomato cultivars and provided protection against Pst race 0 strains for many decades.However, virulent Pst race 1 strains that evade Pto-mediated immunity now predominate in tomato-growing regions worldwide. Here we report the identification of resistance to a Pst race 1 strain (Pst19) in the wild tomato accession S. pimpinellifolium LA1589 (hereafter LA1589), using our rapid high-throughput seedling screen. LA1589 supports less bacterial growth than cultivars, and does not exhibit a hypersensitive response to Pst19. We tested an existing set of 87 Inbred Backcross Lines (IBLs) derived from a cross between susceptible Solanum esculentum E-6203 and Solanum pimpinellifolium LA1589 for resistance to Pst19. Using single-marker analysis, we identified three genomic regions associated with resistance. Bacterial growth assays on IBLs confirmed that these regions contribute to resistance in planta. We also mapped candidate genes associated with resistance in a cross between the Solanum lycopersicum var. lycopersicum cultivar Heinz BG-1706 and S. pimpinellifolium LA1589. By comparing candidates from the two mapping approaches, we were able to identify 3 QTL and 5 candidate genes in LA1589 for a role in resistance to Pst19. This work will assist in molecular marker assisted breeding to protect tomato from bacterial speck disease.

    Keywords: Bacterial speck, genetic diversity, Quantitative Trait Loci (QTL), plant breeding, Pseudomonas syringae, Solanum pimpinellifolium

    Received: 11 Apr 2024; Accepted: 24 Sep 2024.

    Copyright: © 2024 Hassan, Diplock, Chau-Ly, Calma, Boville, Yee, Harris and Lewis. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Jennifer D. Lewis, Plant Gene Expression Center, Agricultural Research Service (USDA), Albany, United States

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