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

Authors: Coyne, Clarice - Clare; Porter, Lyndon; BOUTET, GILES - Institut National De La Recherche Agronomique (INRA); MA, YU - Washington State University; McGee, Rebecca; LESNÉ, ANGELIQUE - Institut National De La Recherche Agronomique (INRA); BARANGER, ALAIN - Institut National De La Recherche Agronomique (INRA); PILET-NAYAL, MARIE-LAURE - Institut National De La Recherche Agronomique (INRA)

Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2019
Publication Date: 3/12/2019
Citation: Coyne, C.J., Porter, L.D., Boutet, G., Ma, Y., McGee, R.J., Lesné, A., Baranger, A., Pilet-Nayal, M. 2019. Confirmation of Fusarium root rot resistance QTL Fsp-Ps 2.1 of pea under controlled conditions. Biomed Central (BMC) Plant Biology. 19:98(2019). https://doi.org/10.1186/s12870-019-1699-9.
DOI: https://doi.org/10.1186/s12870-019-1699-9

Interpretive Summary: Dry pea (Pisum sativum L.) production has increased substantially in the US since 2004 to 0.5 million hectares, primarily in the northern tier states of North Dakota and Montana (USDA NASS, 2018). Following the increase in planting dry pea along with short rotations with cereal crops, an increase of root rots have been reported in the USA. One fungus, a Fusarium species, is one of the main pathogens causing the root rotting in pea field. We have mapped the main DNA region (QTL) controlling high levels of genetic resistance. We screened a pea population segregating for more resistant and more susceptible lines in the greenhouse by inoculating the seed with the pathogen. The population was skimmed sequenced (genotyping-by-sequencing) previously and combined with the greenhouse results two regions controlling resistance were identified. The main region controls 50% of the variation for resistance giving breeders a very useful SNP DNA marker for use in applied pea breeding programs to develop resistant cultivars.

Technical Abstract: 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. pisi (Fsp) is frequently one of the main causal organisms. High levels of partial resistance Fsp has been identified in plant genetic resources. Genetic resistance offers one of the best solutions to this difficult to chemically control root rotting fungus. A recombinant inbred population segregating for high levels of partial resistance, previously 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 QTL. Two 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 0.4-1.0 cM. The second QTL Fsp-Ps3.2 explains only 3.6-4.6% of the variance. Both alleles are contributed by the resistant parent PI 180693. A third QTL Fsp-Ps7.1 is below the threshold but interesting as detected in two previous reports for Fsp resistance. With 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 Fsp.