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.

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First Report of Aphanomyces Root Rot Caused by Aphanomyces euteiches on Field Pea in North Dakota

Plant Disease ◽

10.1094/pdis-06-15-0649-pdn ◽

2016 ◽

Vol 100 (2) ◽

pp. 522 ◽

Cited By ~ 4

Author(s):

K. Zitnick-Anderson ◽

J. S. Pasche

Keyword(s):

North Dakota ◽

Root Rot ◽

Field Pea ◽

Aphanomyces Euteiches ◽

First Report

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Management strategies to reduce losses caused by fusarium seedling blight of field pea

Canadian Journal of Plant Science ◽

10.4141/cjps2012-293 ◽

2013 ◽

Vol 93 (4) ◽

pp. 619-625 ◽

Cited By ~ 8

Author(s):

K. F. Chang ◽

S. F. Hwang ◽

H. U. Ahmed ◽

B. D. Gossen ◽

G. D. Turnbull ◽

...

Keyword(s):

Root Rot ◽

Field Experiments ◽

Management Strategies ◽

Stand Density ◽

Field Trials ◽

Field Pea ◽

Seedling Blight ◽

Inoculum Level ◽

Fusarium Seedling Blight ◽

Disease Pressure

Chang, K. F., Hwang, S. F., Ahmed, H. U., Gossen, B. D., Turnbull, G. D. and Strelkov, S. E. 2013. Management strategies to reduce losses caused by fusarium seedling blight of field pea. Can. J. Plant Sci. 93: 619–625. Fusarium seedling blight can cause substantial reductions in the stand density of field pea in western Canada. In greenhouse experiments, emergence decreased and root rot severity rose with increasing inoculum density. In field trials in 2007 and 2008 near Edmonton, AB, seeding at different depths and seeding dates did not consistently affect emergence or yield in Fusarium-infested soils. In field experiments, emergence declined significantly with each increase in inoculum level. Also, seed yield were reduced at high levels of disease pressure. Treatment of seed with Apron Maxx improved emergence, nodulation and yield of treatments challenged with inoculum of F. avenaceum in both greenhouse and field experiments. This research demonstrates the need to prevent seedling blight and root rot through proper seed treatment.

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First Report of Root Rot of Field Pea Caused by Aphanomyces euteiches in Alberta, Canada

Plant Disease ◽

10.1094/pdis-09-14-0905-pdn ◽

2015 ◽

Vol 99 (2) ◽

pp. 288-288 ◽

Cited By ~ 20

Author(s):

S. Chatterton ◽

R. Bowness ◽

M. W. Harding

Keyword(s):

Root Rot ◽

Lateral Roots ◽

Field Pea ◽

Aphanomyces Euteiches ◽

Fusarium Spp ◽

Specific Primers ◽

Root Cortex ◽

Brown Discoloration ◽

Field Soils ◽

Total Dna

In recent years, root rots have severely impacted yields of field pea (Pisum sativum L.) in the Canadian province of Alberta. Above-normal precipitation levels in the springs of 2011 to 2013 led to the hypothesis that Aphanomyces euteiches Drechsler may play a role in root rot in water-saturated pea fields. To determine causal agent(s) of root rot, 145 pea fields were surveyed at flowering in July 2013 (1). Symptoms of root rot were abundant; the most prominent included red vascular streaking and dark brown rot of the tap root, indicative of Fusarium spp., but brown discoloration and cortical decay of lateral roots, indicative of A. euteiches, was also observed. Total genomic DNA was extracted from diseased root samples from each field, using the Qiagen DNeasy Plant kit, and amplified with species-specific primers for A. euteiches (2). Fusarium spp. were present in all fields, but seven fields located within a 200-km radius yielded a positive reaction for A. euteiches. Five fields were re-visited in May 2014 to collect soil for a bait test (3). Tests were performed using surface-sterilized pea seeds (cv. CDC Meadow) treated with Allegiance FL (Bayer, a.i. metalaxyl) at a rate of 110 ml/kg of seed. Five seeds per pot were planted into field soils in 10-cm pots with 12 replicate pots per field. Soils were irrigated as needed until the second-node stage and then kept at saturation for 14 days. Thirty day-old pea roots were evaluated for root rot symptoms; plated onto cornmeal agar amended with metalaxyl, benomyl, and vancomycin (MBV) without surface sterilization; and visualized microscopically for presence of oospores in the roots. Roots from three out of the five field soils showed symptoms typical of A. euteiches infection, including honey-brown discoloration, degradation of the root cortex, and presence of oospores. Root rot symptoms from the remaining fields were characteristic of Fusarium root rot, and oospores were not observed in roots. Fungal cultures with fast-growing, white, aerial mycelia characteristic of A. euteiches on MBV, were recovered from roots with Aphanomyces root rot symptoms, and transferred to PDA. To confirm pathogen identity, total DNA was extracted from 7-day-old cultures growing on PDA using the Qiagen DNeasy Plant Kit. The ribosomal DNA internal transcribed spacer (ITS) region was amplified using the primer pair ITS1 and ITS4 and sequenced (4). The sequences, deposited in GenBank with accession numbers KM486065, KM486066, and KM486067, were 100% identical to the ITS rDNA sequence of several isolates of A. euteiches using a BLASTn query. Fusarium spp. were also recovered from all root samples in the soil bait test. Total DNA extracted from roots was used in PCR assays with A. euteiches-specific primers as described above. PCR amplification of root DNA was successful only from the same three fields that showed Aphanomcyces root rot symptoms, further verifying presence of A. euteiches. The inability to detect or recover A. euteiches from two fields that had tested positive in the survey was likely due to patchy distribution of this pathogen and emphasizes the importance of rigorous soil collection methods to accurately detect pathogens. Although this is the first record of A. euteiches on field pea in Alberta, the distribution of A. euteiches within a 200-km radius in southern Alberta indicates that it has likely been present in soils for several years. The interaction between A. euteiches and Fusarium spp. infection in the root rot complex of field pea and their impact on field pea production in Alberta is currently being investigated. References: (1) S. Chatterton et al. Can. Plant Dis. Surv. 94:189, 2014. (2) C. Gangneux et al. Phytopathology 104:1138, 2014. (3) D. Malvick et al. Plant Dis. 78:361, 1994. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

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First report of collar and root rot of faba bean caused by Rhizoctonia solani AG-2-2 IIIB in Bangladesh

Plant Disease ◽

10.1094/pdis-08-21-1603-pdn ◽

2021 ◽

Author(s):

S. K. Paul ◽

Dipali Rani Gupta ◽

Nur Uddin Mahmud ◽

A.N.M. Muzahid ◽

Tofazzal Islam

Keyword(s):

Rhizoctonia Solani ◽

Faba Bean ◽

Root Rot ◽

Disease Incidence ◽

Management Strategies ◽

Its Region ◽

Anastomosis Group ◽

Grain Legume ◽

Collar And Root Rot ◽

Wheat Kernels

Faba bean (Vicia faba L.) is an underutilized promising grain legume commercially grown in central and northern part of Bangladesh (Yasmin et al. 2020). In January 2021, faba bean plants exhibiting symptoms of collar and root rot and yellowing of leaves were observed in thirty plots of an experimental field at the Bangladesh Agricultural University (24.75° N, 90.50° E), Mymensingh, Bangladesh. Infected plants had dark brown to black lesions on the roots, extending above the collar region. An average disease incidence and severity was 7.16% and 6.91%, respectively. Eight diseased plants were collected from the field by uprooting one plant from each of eight randomly selected experimental plots and surface disinfected with sodium hypochlorite (0.2%) for 3 min followed by 1 min in ethanol (70%), and then rinsed three times with distilled water and dried on sterile paper towels. Collar and root pieces (5×5 mm) of symptomatic tissues were placed on Potato Dextrose Agar (PDA). Plates were incubated at 25°C for three days and isolates were purified from single-tip culture. The isolates produced brown colored mycelia often with brown sclerotia. Under microscope, fungal colonies exhibited right–angled branching with constriction at the base of hyphal branches and a septum near the originating point of hyphal branch consistent with the description of Rhizoctonia solani Kuhn (Sneh et al. 1991). The isolates grew at 35°C on PDA (5 mm/24). Molecular identification of the isolates BTRFB1 and BTRFB7 was determined by sequencing the rDNA internal transcribed spacer (ITS) region using primers ITS1 and ITS4 (White et al. 1990). A BLAST search showed that the sequences (GenBank Accession nos. MZ158299.1 and MZ158298.1) had 99.28% similarity with R. solani isolates Y1063 and SX-RSD1 (GenBank Accession nos. JX913811.1 and KC413984.1, respectively). Phylogenetic analysis revealed that the present isolates grouped with R. solani anastomosis group AG-2-2 IIIB. To confirm pathogenicity, both isolates were grown individually on sterile wheat kernels at 28°C for 6 days (D’aes et al. 2011). Faba bean seedlings were grown in plastic pots containing sterile potting mix (field soil/composted manure/sand 2:2:1 [v/v]). Two-week-old plants were inoculated by placing five infested wheat seeds adjacent to the roots. Control pots were inoculated with sterile wheat kernels using the same procedure. Plants were placed in a growth room with a 16 h/8 h light/dark photoperiod at 25 ± 2°C after inoculation. Fifteen days after inoculation, typical collar and root rot symptoms were developed on inoculated plants, similar to symptoms observed in the field. Control plants remained non-symptomatic. Finally, six isolates of R. solani were isolated from the symptomatic plants and identified by morphological and molecular analysis. Rhizoctonia solani is the causal agent of seed and root rot, hypocotyl canker, and seedling damping-off diseases of faba bean in many other countries (Rashid and Bernier 1993; Assunção et al. 2011). To our knowledge, this is the first confirmed report of Rhizoctonia solani causing collar and root rot of faba bean in Bangladesh. This finding will be helpful for the development of management strategies to control this disease and to expand the production of faba bean in Bangladesh.

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Exploration of Soil and Weather Factors on Mulberry Root Rot Incidence in the Western Zone of Tamil Nadu, India

International Journal of Environment and Climate Change ◽

10.9734/ijecc/2021/v11i1230552 ◽

2021 ◽

pp. 18-29

Author(s):

M. Saratha ◽

K. Angappan ◽

S. Karthikeyan ◽

S. Marimuthu ◽

K. Chozhan

Keyword(s):

Soil Temperature ◽

Root Rot ◽

Tamil Nadu ◽

Disease Incidence ◽

Research Centre ◽

Soil Parameters ◽

Weather Factors ◽

Soil Borne Pathogens ◽

Western Zone ◽

Cent Disease

Aims: To record the occurrence of mulberry root rot disease, epidemiology, interaction of weather and soil parameters with the soil-borne pathogens in Western zone of Tamil Nadu during 2019-2020. Study Design: Survey. Place and Duration of Study: Surveyed in Coimbatore, Tiruppur, Erode, Dharmapuri and Krishnagiri districts of Tamil Nadu. Laboratory experiments were carried out at Department of Sericulture & Department of Plant Pathology, Tamil Nadu Agricultural University (TNAU), Coimbatore between July 2019 and Jan 2021. Methodology: Per cent disease incidence of root rot was recorded in all surveyed gardens. To analyze the soil and weather parameters, the composite soil samples were subjected to textural analysis and weather data were collected from TNAU Agro Climate Research Centre. To predict soil temperature for all surveyed locations, the model regression equations were derived. The correlation analysis was done between per cent disease incidence, weather and soil parameters. Results: The highest disease incidence was recorded in Nallampalli block of Dharmapuri district (54 per cent) whereas the lowest in Udumalaipettai block of Tiruppur district (0.06 per cent). The infected mulberry root samples yielded complex of soil-borne pathogens including Macrophomina phaseolina, Lasiodiplodia theobromae, Fusarium sp., and pathogenicity was proved. The results revealed that root rot incidence was recorded in all types of cultivars, significantly in ruling variety V1 irrespective of its age, soil type, spacing, and irrigation method. Soil parameters like texture, temperature and moisture content were found to augment the disease. Per cent disease incidence had significantly positive correlation with the weather factors like air and soil temperature whereas negative correlation with relative humidity and rainfall. Conclusion: Synergism of abiotic stress factors hinders the mulberry plant health and increases its susceptibility to the soil-borne pathogens.

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Biological Control of Pathogens Causing Root Rot Complex in Field Pea Using Clonostachys rosea Strain ACM941

Phytopathology ◽

10.1094/phyto.2003.93.3.329 ◽

2003 ◽

Vol 93 (3) ◽

pp. 329-335 ◽

Cited By ~ 49

Author(s):

Allen G. Xue

Keyword(s):

Root Rot ◽

Seed Treatment ◽

Fungal Pathogens ◽

Seedling Emergence ◽

Field Pea ◽

Mycosphaerella Pinodes ◽

Limiting Factor ◽

Aphanomyces Euteiches ◽

Clonostachys Rosea

Pea root rot complex (PRRC), caused by Alternaria alternata, Aphanomyces euteiches, Fusarium oxysporum f. sp. pisi, F. solani f. sp. pisi, Mycosphaerella pinodes, Pythium spp., Rhizoctonia solani, and Sclerotinia sclerotiorum, is a major yield-limiting factor for field pea production in Canada. A strain of Clonostachys rosea (syn. Gliocladium roseum), ACM941 (ATCC 74447), was identified as a mycoparasite against these pathogens. When grown near the pathogen, ACM941 often was stimulated to produce lateral branches that grew directly toward the pathogen mycelium, typically entwining around the pathogen mycelium. When applied to the seed, ACM941 propagated in the rhizosphere and colonized the seed coat, hypocotyl, and roots as the plant developed and grew. ACM941 significantly reduced the recovery of all fungal pathogens from infected seed, increased in vitro seed germination by 44% and seedling emergence by 22%, and reduced root rot severity by 76%. The effects were similar to those of thiram fungicide, which increased germination and emergence by 33 and 29%, respectively, and reduced root rot severity by 65%. When soil was inoculated with selected PRRC pathogens in a controlled environment, seed treatment with ACM941 significantly increased emergence by 26, 38, 28, 13, and 21% for F. oxysporum f. sp. pisi, F. solani f. sp. pisi, M. pinodes, R. solani, and S. sclerotiorum, respectively. Under field conditions from 1995 to 1997, ACM941 increased emergence by 17, 23, 22, 13, and 18% and yield by 15, 6, 28, 6, and 19% for the five respective pathogens. The seed treatment effects of ACM941 on these PRRC pathogens were greater or statistically equivalent to those achieved with thiram. Results of this study suggest that ACM941 is an effective bioagent in controlling PRRC and is an alternative to existing chemical products.

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First Report of Aphanomyces euteiches Causing Aphanomyces Root Rot on Lentil in North Dakota

Plant Disease ◽

10.1094/pdis-11-19-2422-pdn ◽

2020 ◽

Vol 104 (6) ◽

pp. 1876

Author(s):

K. K. Zitnick-Anderson ◽

J. S. Pasche ◽

T. Gargouri-Jbir ◽

A. Kalil

Keyword(s):

North Dakota ◽

Root Rot ◽

Aphanomyces Euteiches ◽

First Report

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Fusarium species associated with root rot of lentil (Lens culinaris L.) in North Dakota

Plant Health Progress ◽

10.1094/php-03-21-0063-rs ◽

2021 ◽

Author(s):

Kimberly Anderson Zitnick ◽

Taheni Gargouri Jbir ◽

Adam Carlson ◽

Shawn Postovit ◽

Julie Pasche ◽

...

Keyword(s):

North Dakota ◽

Root Rot ◽

Lens Culinaris ◽

Management Practices ◽

Fusarium Species ◽

Effective Management ◽

Aphanomyces Euteiches ◽

Previous Survey ◽

Variation Assessment ◽

Isolated Species

Root rot of lentils is caused by a pathogen complex which includes several Fusarium species as well as Aphanomyces euteiches, Rhizoctonia solani and Pythium species. Surveys of lentil fields were conducted in 2016 and 2018 in North Dakota to identify Fusarium species associated with root rot. Isolations were performed from lentil roots exhibiting disease and isolates were identified via morphology and sequencing. In total, 114 fields were surveyed and 391 Fusarium isolates were collected. A diversity of Fusarium species was recovered as ten species were represented; however, F. oxysporum was the most frequently isolated species, present in 71% of fields where Fusarium root rot was detected. Based on correlation with disease severity data, it is likely that some of these isolates are pathogenic. F. avenaceum was relatively uncommon, unlike previous survey efforts on field pea in North Dakota. Further research is needed to determine how the Fusarium population responsible for root rot of lentil may be affected by cropping practices or seasonal climatic variation. Assessment of the virulence and host range of Fusarium species associated with root rot of lentil will further enhance our understanding of the root rot complex in lentil and the development and integration of effective management practices.

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Management of Root Rot (Rhizoctonia solani) of Mothbean through Bio-Agents

Legume Research - An International Journal ◽

10.18805/lr-4242 ◽

2020 ◽

Author(s):

S. L. Godara ◽

Narendra . Singh

Keyword(s):

Grain Yield ◽

Rhizoctonia Solani ◽

Pseudomonas Fluorescens ◽

Trichoderma Harzianum ◽

Root Rot ◽

Seed Treatment ◽

Field Experiments ◽

Disease Incidence ◽

Management Strategies ◽

Soil Application

Root rot caused by Rhizoctonia solani is an important disease of mothbean, under severe infestation it causes 58-68 % losses in grain yield. Three-year field experiments were conducted in hot arid conditions at Bikaner, Rajasthan during kharif seasons with the objective to find out suitable eco-friendly management strategies for root rot. The experiment was conducted on cv. RMO-225 with six different combination of Trichoderma harzianum + Pseudomonas fluorescens bio- agents viz, seed treatment, soil treatment and their combinations against the root rot disease and compared with an untreated control. Results of experiment showed that all the treatments brought significant decline in disease incidence and consequently enhancement of grain yield compared to control. The treatment having combination of Trichoderma harzianum + Pseudomonas fluorescens seed treatment (4+4 g/kg seed) + soil application of T. harzianum + P. fluorescens (1.25 +1.25 kg in 50 kg FYM for each/ha) had minimum (21.78 %) root rot incidence, highest grain yield (10.56 q /ha) and net return (Rs. 14,338/ha). The T. harzianum seed treatment 8 g/kg seed + soil application of T. harzianum 2.5kg in 100 kg FYM/ha was the next best treatment with 25.56 per cent disease incidence and 9.42 q/ha of grain yield. These treatments can provide an effective, economical and eco- friendly management of root rot of mothbean for cultivators.

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