Associations among the communities of soil-borne pathogens, soil edaphic properties and disease incidence in the field pea root rot complex

Abstract

Background and aims Field pea production is greatly impacted by multiple soil-borne fungal and oomycete pathogens in a complex. The objectives of this research were to 1) identify the soil-borne pathogens associated with field pea in North Dakota and; 2) develop prediction models incorporating the occurrence of the soil-borne pathogen communities, soil edaphic properties and disease incidence. Methods Soil and plants were sampled from 60 field pea fields in North Dakota during 2014 and 2015. Plants (1500 across two years) were rated for both root rot and soil-borne pathogens isolated from roots. Soils were analyzed for edaphic properties. Indicator species analysis was used to identify soil-borne pathogen communities. Logistic regression was used to determine associations and develop prediction models. Results Survey results from 2014 and 2015 indicated that the most prevalent soil-borne pathogens identified in field pea fields were Fusarium spp. and Aphanomyces euteiches. Five soil-borne pathogen communities were identified; three of which had statistically significant associations characterized by (1) Fusarium acuminatum, (3) A. euteiches, and (4) Fusarium sporotrichioides. The occurrence of the three communities were associated with clay content, soil pH, Fe2+, and K+. Disease incidence was associated with the presence of either community 1 or 3 and K+. Conclusions The results generated from this research will contribute to the development of management strategies by providing a soil-borne pathogen community prediction tool.

Soil Microbial Indicators within Rotations and Tillage Systems

“…F. sporotrichioides (S) is a common, ineffectual agricultural and grassland pathogen [98], commonly isolated from corn and other cereal crops [99]. F. sporotrichioides (S) RAs have been reported to be negatively associated with soil pH [100], as is the case in this study showing greater RAs from the CCC rotation, which has significantly lower pH compared to the other rotations [25]. Behnke, Zabaloy, Riggins, Rodriguez-Zas, Huang and Villamil [25] also found that fungal ITS gene copy numbers were increased in the CCC rotation compared to SSS.…”

Identification of Quantitative Trait Loci Associated With Partial Resistance to Fusarium Root Rot and Wilt Caused by Fusarium graminearum in Field Pea

“…Five single-spore isolates (SSI), S4C ( F. solani ), F4A ( F. avenaceum ), F037 ( F. acuminatum ), F039 ( F. proliferatum ), and FG2 ( F. graminearum ), representing the Fusarium species most frequently recovered from symptomatic pea plants in root rot surveys in Alberta, were used to screen the parental cultivars “00-2067” and “Reward.” Briefly, to obtain the SSIs, surface-sterilized pieces of root tissue with disease lesions were placed on potato dextrose agar (PDA) and incubated at 25°C for 2–3 days and then transferred to the peptone-pentachloronitrobenzene (PCNB) medium for further selection. Mycelial tips of the fungal isolates were cut from selected colonies under a stereomicroscope (Zeiss Axio Scope A1, Carl Zeiss Canada Ltd., Canada), and the water agar (WA) procedure was used to obtain SSI ( Zitnick-Anderson et al, 2020 ). The species designation of each of the SSIs was confirmed based on morphology and evaluation with the PCR primer sets ITS4/ITS5 and EF-1/EF-2, while isolate virulence was confirmed by fulfilling Koch’s postulates ( Feng et al, 2010 ; Chen et al, 2014 ; Zhou et al, 2014 ; Wu et al, 2017 ; Chang et al, 2018 ; Zitnick-Anderson et al, 2018 ).…”

Pea Breeding for Resistance to Rhizospheric Pathogens

“…On the other hand, monogenic resistance is easy to select and has been achieved in some soilborne diseases of legumes, but the rapid evolution of pathogens can easily break down the existing levels of resistance. So, the understanding and evaluation of soilborne diseases by efficient identification and screening techniques is a requirement for the implementation of effective control strategies and resistance breeding [ 49 , 52 ]. Therefore, in this review, some of the important pea rhizospheric diseases are deliberated.…”

“…The identification of resistance sources within germplasms and a combination of practical phenotypic evaluation standards and host resistance genotyping can improve sustainable Fo p control strategies in the long term [ 57 , 75 , 76 ]. So, the knowledge of the fungal patho-systems, genetics and physiological variations can inform sustainable resistance breeding strategies [ 52 , 64 ]. Qualitative resistance for Fop race 1, 5 and 6 have been identified and deployed into pea varieties using classical breeding [ 62 , 77 ].…”

“…Consequently, it is paramount to use eco-friendly techniques to manage the pathogen. Thus, several measures for the sustainable improvement of pea against this rot complex are well-established [ 52 ]. Resistance to seedling rot caused by R. solani is linked with seedling epicotyl thickness and age, with younger seedlings being more susceptible to infection [ 63 , 125 ].…”