Confirmation of Fusarium root rot resistance QTL Fsp-Ps 2.1 of pea under controlled conditions

Clarice J Coyne,Gilles Boutet,Rebecca J Mcgee,Marie-Laure Pilet-Nayel,Alain Baranger,Lyndon D Porter,Angélique Lesné,Yu Ma

doi:10.1186/s12870-019-1699-9

Abstract

BackgroundDry pea production has increased substantially in North America over the last few decades. With this expansion, significant yield losses have been attributed to an escalation in Fusarium root rots in pea fields. Among the most significant rot rotting pathogenic fungal species, Fusarium solani fsp. pisi (Fsp) is one of the main causal agents of root rot of pea. High levels of partial resistance to Fsp has been identified in plant genetic resources. Genetic resistance offers one of the best solutions to control this root rotting fungus. A recombinant inbred population segregating for high levels of partial resistance, previously single nucleotide polymorphism (SNP) genotyped using genotyping-by-sequencing, was phenotyped for disease reaction in replicated and repeated greenhouse trials. Composite interval mapping was deployed to identify resistance-associated quantitative trait loci (QTL).ResultsThree QTL were identified using three disease reaction criteria: root disease severity, ratios of diseased vs. healthy shoot heights and dry plant weights under controlled conditions using pure cultures of Fusarium solani fsp. pisi. One QTL Fsp-Ps 2.1 explains 44.4–53.4% of the variance with a narrow confidence interval of 1.2 cM. The second and third QTL Fsp-Ps3.2 and Fsp-Ps3.3 are closely linked and explain only 3.6–4.6% of the variance. All of the alleles are contributed by the resistant parent PI 180693.ConclusionWith the confirmation of Fsp-Ps 2.1 now in two RIL populations, SNPs associated with this region make a good target for marker-assisted selection in pea breeding programs to obtain high levels of partial resistance to Fusarium root rot caused by Fusarium solani fsp. pisi.

Highlights

Dry pea production has increased substantially in North America over the last few decades
The objective of this study was to determine quantitative trait loci (QTL) associated with high levels of partial resistance to fsp. pisi (Fsp) in a second RIL population (Baccara × PI 180693) under controlled conditions using a higher density single nucleotide polymorphism (SNP)-based linkage map called “BP-Duarte” [26]
In terms of environmental effects, there were no significant differences in all traits (Pdisease severity = 0.19, Pplant weight = 0.21, and Pplant height = 0.20) using the mixed linear model frequently employed in QTL studies

Summary

Introduction

Dry pea production has increased substantially in North America over the last few decades. With this expansion, significant yield losses have been attributed to an escalation in Fusarium root rots in pea fields. Among the most significant rot rotting pathogenic fungal species, Fusarium solani fsp. High levels of partial resistance to Fsp has been identified in plant genetic resources. Pathogens associated with the root disease complex of pea, recently reviewed in Tran et al [9], include Aphanomyces euteiches, Fusarium species, Phoma pinodella, Didymella pinodes, Pythium spp., Thielaviopsis basicola and Rhizoctonia solani. F. solani f. sp. pisi (Fsp), F. acuminatum, F. avenaceum, F. culmorum, F. graminearum, F. sambucinum, F. equiseti, F. oxysporum, F. poae, F. redolens, F. sporotrichioides and F. tabacinum were found pathogenic to varying

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