Aphanomyces euteiches: A Threat to Canadian Field Pea Production

Wu, Liren; Chang, K. F.; Conner, Robert L.; Strelkov, Stephen E.; Fredua-Agyeman, Rudolph; Hwang, Sheau‐Fang; Feindel, David

doi:10.1016/j.eng.2018.07.006

Cited by 40 publications

(43 citation statements)

References 83 publications

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“…Aphanomyces euteiches has recently emerged as a challenging root pathogen in western Canada, that is not limited to specific soil or land use types [ 29 ]. Root rot diseases caused by this soil-borne oomycete fungus results in substantial losses in pulse crop production, especially under environmental conditions that promote the pathogen growth and development [ 30 , 31 , 32 ]. Infection results in symptoms of brown-stained roots, generally similar among all infected legumes, leading to poor growth and death of plants.…”

Section: Introductionmentioning

confidence: 99%

“…The fungus is adapted to wet soil conditions, and persistent cycles of wet weather in recent years have caused changes in field conditions that have resulted in significant problems with Aphanomyces root rot (ARR) in western Canada, particularly affecting lentil- and pea-growing regions. To date there are no effective control measures for ARR [ 31 , 33 ]. The best approach for the control of ARR could be prevention, sanitation (removal of infected plant material), use of resistant varieties, and improved management practices including crop rotation, promotion of healthy plant growth, and better soil drainage.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Lentil Genotype on the Colonization of Beneficial Trichoderma Species and Biocontrol of Aphanomyces Root Rot

et al. 2020

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Trichoderma species are opportunistic plant symbionts that are common in the root and rhizosphere ecosystems. Many Trichoderma species may enhance plant growth, nutrient acquisition, and disease resistance, and for these reasons, they are widely used in agriculture as biofertilizers or biocontrol agents. Host plant genotype and other microorganisms, such as root pathogens, may influence the efficacy of Trichoderma inoculants. Aphanomyces euteiches is an important soil-borne oomycete in western Canada that causes root rot in legume crops such as lentil and pea, and there is not yet any significantly resistant varieties or effective treatments available to control the disease. In this study, the composition of root-associated fungal communities and the abundance of Trichoderma species, T. harzianum strain T-22 and T. virens strain G41, was determined in the roots of eight Lens genotypes based on internal transcribed spacer (ITS) Illumina MiSeq paired-end sequencing, both in the presence and the absence of the root rot pathogen Aphanomyces euteiches. Biocontrol effects of T. harzianum on A. euteiches was also examined. Significant genotypic variations were observed in the composition of root-associated fungal communities and the abundance of the different Trichoderma species in the lentil roots. The presence of A. euteiches altered the composition of Trichoderma found associated to the lentil genotypes. Biocontrol of A. euteiches by T. harzianum T22 species was observed in vitro and positive correlations between the abundance of Trichoderma and plant root and shoot biomass were observed in vivo. These findings revealed that lentil genotype and infection by the phytopathogen A. euteiches greatly influenced the colonization of root-associated fungi and the abundance of the Trichoderma species, as well as the effect on plant growth promotion. The multipartite interactions observed among lentil genotypes, Trichoderma species and A. euteiches suggest possibilities to select compatible host-beneficial microbe combinations in lentil breeding programs and to develop application strategies to harness the beneficial effects of Trichoderma inoculants in sustainable crop production systems.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Lentil Genotype on the Colonization of Beneficial Trichoderma Species and Biocontrol of Aphanomyces Root Rot

et al. 2020

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“…The disease is caused by the oomycete pathogen Aphanomyces euteiches, which infects pea plants via zoospores and (or) mycelia at any growing stage (Hughes and Grau 2013). Moreover, this oomycete produces oospores that can survive for more than 10 yr in soil under adverse conditions (Hughes and Grau, 2013;Wu et al 2018). Aphanomyces root rot symptoms are detected belowground (early-stage symptoms) and aboveground (late-stage symptoms).…”

Section: Introductionmentioning

confidence: 99%

Isolation, identification, and assessment of soil bacteria as biocontrol agents of pea root rot caused by Aphanomyces euteiches

2020

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Aphanomyces euteiches is a soil-borne pathogen that causes root rot of pea and can significantly affect pea production in western Canada. This study aimed to isolate and identify soil bacteria with antagonistic activity towards A. euteiches mycelial and zoospore developmental stages under in vitro conditions and assess their potential as biocontrol agents against aphanomyces root rot in field pea under growth chamber conditions. In vitro screening of soil bacteria identified 184 antagonistic isolates, including 22 from an existing culture collection. Mean mycelial growth inhibition zones ranged from 1 to 12 mm, and mean zoospore germination inhibition ranged from 0% to 100%. Use of 16S rDNA sequence analysis placed isolates into 18 different bacterial genera. Screening of 47 bacteria that inhibited both infective stages identified 29 potential biocontrol strains, including Rhizobium spp. that significantly (α = 0.05) suppressed aphanomyces root rot in field pea grown in vermiculite, suggesting the intriguing possibility of using N-fixing Rhizobium inoculants as biocontrol agents for aphanomyces control. Further screening of 20 isolates as soil inoculants identified K-Hf-L9 (Pseudomonas fluorescens), PSV1-7 (Pantoea agglomerans), and K-Hf-H2 (Lysobacter capsici) isolates as having the highest biocontrol activity, significantly (α = 0.05) suppressing aphanomyces root rot in field pea in growth chamber trials. This study demonstrates the possibility of aphanomyces root rot management using biocontrol agents.Résumé : Aphanomyces euteiches est un agent pathogène du sol responsable du piétin du pois. Ce champignon nuit parfois de façon importante à la production de cette légumineuse dans l'Ouest canadien. Les auteurs voulaient isoler puis identifier les bactéries du sol susceptibles d'agir in vitro contre le mycélium et les zoospores d'A. euteiches, et établir si on pourrait s'en servir comme moyen de lutte biologique contre le piétin du pois de grande culture en chambre de croissance. La sélection in vitro de bactéries telluriques a débouché sur l'identification de 184 isolats antagonistes, dont 22 d'une collection de cultures existante. Les plages moyennes d'inhibition de la croissance du mycélium varient de 1 à 12 mm et le degré moyen d'inhibition de la germination des zoospores, de 0 à 100 pour cent. Le séquençage de l'ADNr 16S situe les isolats dans 18 genres bactériens. L'examen de 47 bactéries inhibant les deux stades infectieux ont permis d'identifier 29 souches susceptible de servir à la lutte biologique, y compris des espèces du genre Rhizobium supprimant de manière significative (α = 0,05) le piétin causé par Aphanomyces chez le pois cultivé dans de la vermiculite, signe d'un intrigante possibilité où l'inoculation de Rhizobium fixateur d'azote permettrait aussi de lutter contre la maladie. Une étude plus poussée de 20 isolats comme inoculants a permis d'établir que les souches K-Hf-L9 (Pseudomonas fluorescens), PSV1-7 (Pantoea agglomerans) et K-Hf-H2 (Lysobacter capsici) ont la plus forte activité antagonis...

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“…Disease symptoms begin with healthy white roots turning honey brown. In later stages, roots turn brown, the hypocotyl darkens at the soil line and eventually the plants wilt (Gaulin et al 2007;Wu et al 2018). A. euteiches is a filamentous plant pathogen belonging to the Oomycetes with both asexual and sexual stages.…”

Section: Introductionmentioning

confidence: 99%

Effects of biocontrol bacteria and earthworms onAphanomyces euteichesroot-rot and growth of peas (Pisum sativum) studied in a pot experiment

Lagerlöf

Ayuke

Heyman

et al. 2020

Acta Agriculturae Scandinavica, Section B — Soil & Plant Sc

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The role of below-ground interactions between microbial biocontrol agents and soil fauna for combatting soil-borne plant diseases have not been studied sufficiently. This study tested the hypothesis that the beneficial bacterium Bacillus velezensis UCMB5113 and the anecic earthworm Lumbricus terrestris positively influence health and growth of peas (Pisum sativum L.) infested with the pathogen Aphanomyces euteiches causing root-rot disease. A greenhouse fully factorial experiment studied the effects of A. euteches, B. velezensis and L. terrestris on the emergence, growth and health of pea plants. The factors B. velezensis and L. terrestris resulted in taller plants (p = .003 and p = .030). B. velezensis treatment resulted in a higher biomass of shoots and roots (p ≤ .001 and p = .005). The effects increased with the presence of both factors (p = .036). Earthworms reduced the disease symptoms significantly (p = .032). The decreased disease symptoms caused by the earthworms might be due to the consumption of A. euteiches (direct effect) as well as soil disturbance (indirect effect). Interactions between the microorganisms added and the earthworms were shown. B. velezensis and L. terrestris can be useful for enhancement of plant growth and for biological control of root-rot in peas.

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Aphanomyces euteiches: A Threat to Canadian Field Pea Production

Cited by 40 publications

References 83 publications

Effects of Lentil Genotype on the Colonization of Beneficial Trichoderma Species and Biocontrol of Aphanomyces Root Rot

Effects of Lentil Genotype on the Colonization of Beneficial Trichoderma Species and Biocontrol of Aphanomyces Root Rot

Isolation, identification, and assessment of soil bacteria as biocontrol agents of pea root rot caused by Aphanomyces euteiches

Effects of biocontrol bacteria and earthworms onAphanomyces euteichesroot-rot and growth of peas (Pisum sativum) studied in a pot experiment

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