Clubroot Symptoms and Resting Spore Production in a Doubled Haploid Population of Oilseed Rape (Brassica napus) Are Controlled by Four Main QTLs

Andrea Botero-Ramírez; Anne Laperche; Solenn Guichard; Mélanie Jubault; Antoine Gravot; Stephen E Strelkov; Maria J Manzanares-Dauleux

doi:10.3389/fpls.2020.604527

Clubroot Symptoms and Resting Spore Production in a Doubled Haploid Population of Oilseed Rape (Brassica napus) Are Controlled by Four Main QTLs

Front Plant Sci. 2020 Dec 17:11:604527. doi: 10.3389/fpls.2020.604527. eCollection 2020.

Authors

Andrea Botero-Ramírez¹, Anne Laperche², Solenn Guichard², Mélanie Jubault², Antoine Gravot², Stephen E Strelkov¹, Maria J Manzanares-Dauleux²

Affiliations

¹ Department of Agricultural, Food and Nutritional Sciences, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, AB, Canada.
² Institut de Génétique, Environnement et Protection des Plantes, INRAE, Institut Agro, Université de Rennes 1, Le Rheu, France.

Abstract

Clubroot, caused by Plasmodiophora brassicae Woronin, is one of the most important diseases of oilseed rape (Brassica napus L.). The rapid erosion of monogenic resistance in clubroot-resistant (CR) varieties underscores the need to diversify resistance sources controlling disease severity and traits related to pathogen fitness, such as resting spore production. The genetic control of disease index (DI) and resting spores per plant (RSP) was evaluated in a doubled haploid (DH) population consisting of 114 winter oilseed rape lines, obtained from the cross 'Aviso' × 'Montego,' inoculated with P. brassicae isolate "eH." Linkage analysis allowed the identification of three quantitative trait loci (QTLs) controlling DI (PbBn_di_A02, PbBn_di_A04, and PbBn_di_C03). A significant decrease in DI was observed when combining effects of the three resistance alleles at these QTLs. Only one QTL, PbBn_rsp_C03, was found to control RSP, reducing resting spore production by 40%. PbBn_rsp_C03 partially overlapped with PbBn_di_C03 in a nucleotide-binding leucine-rich repeat (NLR) gene-containing region. Consideration of both DI and RSP in breeding for clubroot resistance is recommended for the long-term management of this disease.

Keywords: Plasmodiophora brassicae; Rhizaria; clubroot; linkage analysis; oilseed rape; quantitative resistance.