MANAGEMENT AND POPULATION DYNAMICS OF CEREAL PATHOGENS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1002597
• Project No.: MONB00246
• Project Start Date: Oct 1, 2014
• Project End Date: Sep 30, 2019

Project Director
Dyer, AL.

Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717

Performing Department
Plant Sciences and Plant Pathology

Non Technical Summary
OBJECTIVE 1. Introgress resistance into locally adapted wheat germplasm for soilborne pathogens. This project will develop locally adapted hard red wheat germplasm with resistance to root lesion nematode (Pratylenchus neglectus) and Fusarium crown rot (F. pseudograminearum); two important disease problems facing wheat production in Montana. Use of these lines will result not only in more stable and improved yields but will also enhance the yields of subsequent susceptible crops that may follow in rotation. In addition, molecular markers will be identified that will assist in the future selection of resistance in wheat cultivars for Montana and the United States.OBJECTIVE 2. Develop integrated practices for management of root and crown diseases. This project will assess how change population dynamics for nematodes and wireworms will affect alternate diseases that depend on these pests for the creation of infection courts. The benefits will be a improved risk assessments and recommendations for the alternate diseases and an improved assessment of relative importance of root lesion nematodes and wireworms to overall crop losses.OBJECTIVE 3. Investigate the ecology and epidemiology of soilborne pathogens.This project will result in a greater understanding of the role root microbiomes play in root diseases of wheat as well as the role antagonism plays among root and crown pathogens. This work will assist in the selection of control measures that minimize negative perturbations to the natural ecology of the system as well as identify potential bio-rational approaches to root disease management.

Animal Health Component

0%

Research Effort Categories

Basic

25%

Applied

60%

Developmental

15%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	1549	1160	60%
212	1549	1081	20%
102	1549	1070	20%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
1549 - Wheat, general/other;

Field Of Science
1160 - Pathology; 1070 - Ecology; 1081 - Breeding;

Keywords

root lesion nematode

fusarium crown rot

wheat

microbiome

pratylenchus

fusarium

Goals / Objectives
OBJECTIVE 1. Introgress disease resistance into locally adapted wheat germplasm for soilborne wheat pathogens.OBJECTIVE 2. Develop integrated practices for management of root and crown diseases.OBJECTIVE 3. Investigate the ecology and epidemiology of soilborne pathogens.

Project Methods
Objective 1. Introgress resistance into locally adapted wheat germplasm for soilborne pathogens.Develop molecular markers for RLN resistance: Molecular markers of root lesion nematode resistance would speed the development of RLN resistant wheat lines. To accomplish this, Persia 20/Yellowstone progeny (BC1F4-6) where Yellowstone is the recurrent parent are being evaluated for root lesion nematode resistance and the genome of the two parents are being surveyed for single nucleotide polymorphic makers (SNPs(68)). Molecular markers linked to resistance will be identified by examining how polymorphic markers co-segregate with variation in nematode resistance in the BC1F4 progeny lines. To confirm these molecular linkages, a cross of Persia 20 (the resistant parent) with RLN susceptible spring wheat cultivar "McNeal" is currently being advance to the F3 generation. Sixty of these F3 progeny from this second cross will be used to validate molecular markers linked to resistances from the Yellowstone/Persia 20 crosses. The screening of progeny from this second cross will also identify lines for advancing root lesion nematode resistance into spring wheat lines as well. Two additional crosses were performed by Dr. Bruckner with alternative sources of root lesion nematode resistance (Yellowstone/GS50a and Yellowstone/AUS28451R). These have been advanced to BC1F4. Specific lines will be selected from these crosses for their superior agronomic traits and root lesion nematode resistance. These two alternate sources of resistance to root lesion nematode may be important in the future for long term management of Pratylenchus neglectus and other root lesion nematode species that attack cereals.Evaluating agronomic traits of RLN and FCR resistant winter wheat lines: Currently, the 50 most RLN resistant winter wheat lines and the 100 most FCR resistant lines as determined by greenhouse assays are growing in the field (66; 67). These lines will be evaluated for yield, kernel weight and grain protein. These quality measures will be used to select lines for advancing through additional backcrosses with the locally adapted Yellowstone and to move towards statewide trials.Advance RLN and FCR resistance in spring wheat lines: The development of spring wheat varieties would highly desirable. This would provide growers with additional options for root lesion nematode and FCR affected fields and due the short generations times, spring wheat represents a more rapid pathway to the introgression of new resistance in to Montana adapted wheat. Resistances advanced into winter wheat would also be useful to spring wheat as well. Initial crosses have been made for this purpose and will be advanced to BC1F5 prior to disease screening and selection of lines for additional development.Objective 2. Develop integrated practices for management of root and crown diseases. Determine the effects root lesion nematodes (Pratylenchus neglectus) have on crown rot diseases within wheat fields.Field trials will be established in 2015 and 2016 to assess the effects of root lesion nematode populations (P. neglectus) on crown rot severity caused by Fusarium spp. as well as by Cochliobolus sativus. For this, 60 spring wheat plots will be established at each of three locations where root lesion nematodes are known to occur. To assure disease pressure, 20 of the plots will be inoculated in furrow with Fusarium pseudograminearium and 20 plots will be inoculated with Cochliobolus sativus. In the spring, populations of root lesion nematodes for each plot will be measured using previously established methods (2). At the end of the season, disease severity as well as populations of Fusarium and Cochliobolus will be measured for each plot using real-time quantitative methods (73; 74). The resulting data will be analyzed for correlations between root lesion nematode populations and fungal pathogen populations. Additional trials will be set up later to evaluate whether control measures designed to manage Fusarium crown rot such as reduced seedling rates and planting of tolerant wheat varieties are cost effective under the condition of reduced nematode populations.Determine the effects of wireworm populations on the incidence and severity of Cephalosporium stripe.Greenhouse trials will be established to determine the impacts Montana's dominant wireworms species have on Cephalosporium strip infection rates following previously reported methods (28). To accomplish this, 3 wireworms collected in collaboration with Dr. Kevin Wanner will be placed into 20 120cm pots and planted with 10 seed of susceptible winter wheat cultivar Yellowstone. A parallel set of pots will be left un-infested. Four weeks after planting, all pots will subject to a 5 minute dip in a Cephalosporium gramineum spore suspension. The pots will then be placed in a cold room for an 8 week vernalization and then re-placed in the greenhouse. Six weeks after vernalization, pots will be observed for Cephalosporium stripe symptoms. A field study will be conducted in conjunction with the greenhouse study to see if insecticidal seed treatments used to control wireworms affect severity of Cephalosporium stripe in the field.Objective 3. Investigate the ecology and epidemiology of soilborne pathogensA preliminary survey of fungal communities in wheat crowns from fields inoculated and un-inoculated with Fusarium pseudograminearum indicate that Fusarium has dramatic effects on fungal communities (see: Figure 1 page 11). This includes the dramatic reduction in populations of three Phaesophaeria species and increases in populations of Chaetomium glubosum, a noted Fusarium antagonist. In light of these results a broader community survey is proposed to assess Fusarium's community effects in full.Proposed Work:Examine the effects Fusarium infections have on microbiome within wheat crowns. Sixty, four-row plots of spring wheat cultivar 'Vida' were established in the spring of 2013 at both the Fort Ellis and the Arthur H. Post Research Stations. Using protocols that routinely achieve 90% infection rates three wheat plots were inoculated for each of 16 locally collected F. pseudograminearum isolates. The remaining 12 plots were left un-inoculated as controls. Plots were maintained during the growing season of the trial according to standard farming practices. Post-harvest, plots were kept fallow using hand cultivation to control weeds and volunteer wheat thereby eliminating the effects that herbicides would have on fungal communities. Sampling of plots occurred at harvest in early August, 2013 as well as in early October, 2013, two months post-harvest. For each plot and time point, 500 crowns were collected and bulked as single sample for DNA extraction following established protocols. The resulting DNA samples will be assessed for Fusarium population sizes using quantitative real-time PCR and will be analyzed for community effects using pyrosequencing of internal transcribe spacer regions (ITS) and the D1-D2 large ribosomal subunit (LSU) constituents within the DNA samples. The ITS sequence data will be analyzed for qualitative differences among stubble communities, particularly identifying major fungal players within each community. The LSU data will be analyzed for phylogenetic as well as quantitative differences among communities (β community diversity) as visually displayed in principal component plots. The latter community assessments provide non-obvious information on community functions and inter-connections and will be used to examine the relationship between community-wide effects and Fusarium survival. Along with the fungal community analyses, a cursory analysis of bacterial communities will be assessed using the small subunit ribosomal RNA sequences for the first sampling date and if initial results warrant, additional bacterial community analyses will be conducted.

Progress 10/01/14 to 09/30/19

Outputs
Target Audience:This project targets small grain producers as well as researchers with mycology or plant pathology approaches. This program is also focused on the training of new farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Currently the project has two graduate students and employes three undergraduates. The project's results are also integrated in the PI's undergraduate course "Concepts in Plant Pathology" and in senior research projects for 4 undergraduate students in crop science and plant biotechnology. How have the results been disseminated to communities of interest?These results have been desminated in one journal article in plant disease, an abstract presented at the Northwest Divisional Meeting of the American Phytopathological Society and two field day presentations for growers in central Montana. What do you plan to do during the next reporting period to accomplish the goals?For the next reporting session, we hope to release a spring wheat line with improved tolerance to crown rot pathogens and to test deployment strategies for our root lesion nematode resistant winter wheat lines. The hope is to have a RLN resistant cultivars released in by 2022. This will be dependent on agronomic evaluation by winter wheat breeding program, Dr. Phil Bruckner. In addition, we hope to have publications submittted that explore the impact of Fusarium pseudograminearum on downy brome and a thesis defense examining herbicide resistance in Kochia and the impacts of rotational crops has on its lifecycle.

Impacts
What was accomplished under these goals? This project has developed winter wheat lines with resistance to root lesion nematodes and has identified nematode populations that are virulent on barley and lentils. These are firsts for United States for the former and internationally for the latter. The next stage for this project is to understand the impacts of nematode resistant wheat on overall root health for wheat and other crops grown in rotation with wheat and to identify the best deployment strategies for the RLN resistant winter wheat lines.

Publications

• Type: Other Status: Awaiting Publication Year Published: 2019 Citation: Root lesion nematode resistance has been advanced in winter wheat lines. E. E. Gunnunk-Troth, D. B. May, A. T. Dyer. Abstract Northwestern Div APS Phytopathology
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Pathotypes Detected Among Populations of Pratylenchus neglectus Collected From Montana Riyadh T. Al-Khafaji, Erin E. Gunnink Troth, Kris N. Lambert, Jeffrey A. Johnston, and Alan T. Dyer. 2019. Plant Disease, Vol. 103, No. 12: 3259-3264. https://apsjournals.apsnet.org/doi/10.1094/PDIS-12-18-2234-RE?ai=rs&ui=4lq&af=T

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Agricultural Students, Wheat and Pulse Producers, and Agricultural Scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We have employed three undergraduates and one doctoral student in the program over the reporting period. The doctoral student successfully defended his thesis and is now employed in Iraq. The program has also provide undergraduate instruction in the form of a teaching assistantship forintroductory plant pathologyand program director has served on one additional doctoral committee. The program has provide instruction for growers at four events with a combined audience of approximately 120. How have the results been disseminated to communities of interest?Results have been deseminated through four grower meetings, one doctoral thesis and one journal publication. What do you plan to do during the next reporting period to accomplish the goals?The program will continue to advance our breeding for diseas resistance in wheat and in the next stages examine the impactsdeployment of resistant varietieswill have on crop production and management of disease problems on wheat and rotational crops commonly grown incombinations with wheat. The program expects to explore the consequence pathogen on pathogen competition has on trait selection and species distribution in Montana and the Pacific Northwest.

Impacts
What was accomplished under these goals? Obj 1:Advanced spring wheatcrown rot resistant linesare in the second year ofagronomic evaluations. Several of these line are displaying superior performance relative to parental lines. This establishes proof of concept for trait selection and introgression strategies. The procedure will be repeated with different spring wheat backgrounds. Winter wheat lines with good resistance to root lesion nematodes have been identified in greenhouse trials and will now be evaluated for agronomic performance. Obj 2: Reassessment of root lesion nematode impacts in Montana have demonstrated the power of diverse rotations on management these root pests as populations are dramatically lower than previously reported. Objective 3: Our report oncompetition between Fusarium and Cochliobolus represents the first such report between fungal pathogens as documented in the field settings. The work opens new venues for exploring community dyamics for root disease complexes where responses to management practices are often non-intuitive.

Publications

• Type: Theses/Dissertations Status: Accepted Year Published: 2018 Citation: Al-Khafaji, R. 2018. An Assessment of Nematodes Affecting Wheat in Montana. doctoral thesis. 107p
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Troth, Erin, E. Gunnink, Johnston, J.A., Dyer, A.T. 2018. Competition Between Fusarium pseudogramienarum and Cochliobolus sativus observed in field and greenhouse studies. Phytopathology: 108: 215-222.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:This project interacts with small grain growers, plant breeders, plant pathologist and microbial ecologist. It seeks to understand the dynamics of complex pathogen communities in the rhizopshere of cereal crops to provide better disease manage strategies. Changes/Problems:I am starting collaborations with Drs. Mac Burgess and Kevin McPhee. What opportunities for training and professional development has the project provided?The project director has taken on the advising and management of the Crop Science program at Montana State University.The program hascurrently enrolls46undergraduate students and is primarily dedicated to the training of our next generation of growers in Montana. The PD course is the top rated course within the program. In addition he has one graduate student and two undergradaute conducting research in his laboratory. The PD sits on three additional doctoral committees. The program has also made a presentation on regional ag radio program. How have the results been disseminated to communities of interest?There have been three regional presentations as well as two extension publications that engage scientist and growers both locally and across the country. The program has also shared seed treatment data with plant pathologists in Kentucky and Kansas. What do you plan to do during the next reporting period to accomplish the goals?Our program seek to move some portions of breeding program into final phases prior to release. This include materials for management of crown diseases and nematode resistances. We continue to work on the development of an universal diagnostic tools and understanding the function of disease complexes. In the coming years, we along with others will seek to provide tools to growersto better managechloride deficiency and salinity for the primary crops of Montana.

Impacts
What was accomplished under these goals? The program is introgressing resistance to six diseases and have advance lines for three of these disease are going into final testing prior to statewide trials.On the ecological front, ourmost recent work identified a competitive interactions between Fusarium pseudograminearum and Cochliobolus sativus. This is the first identification of competition between fungal pathogens in the field and partially explains why controling onepathogen does not result in expect improvement in crop yield. Our most recent endeavor is to examine chloride deficiency and salt tolernace in wheat (winter, spring and durum) as well as in legumes(field pea, chickpea and lentils).

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Natural history of Fusarium pseudograminearum. Symposium: Plant Pathology into the 21st Century, Cornell University, Ithaca NY.
• Type: Other Status: Published Year Published: 2017 Citation: Berg, J., Bruckner, P., Bergman, J., Bohannon, B., Briar, S., Carr, P., Chen, C., Cook, C., Garza, R., Kephardt. K., Lamb, P., Miller, J.H., Pradhan, G., Reddy, G., Stougard, R., Wichman, D., Dyer, A., Holen, D., Nash, D., Larson, R., Rimel, H. 2017. 2017 Winter Wheat Varieties: Performance evaluation and recommendations.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Al-Khafaji, R., Dyer, A.T., 2017. An assessment of plant parasitic nematodes associated with Montanas wheat and barley. APS Pacific Division.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Gunnink-Troth, E., Johnston, J., Dyer, A.T., 2017. Development of a rapid nanopore diagnostic system (RNDS) for plant pathogens of wheat. APS Pacific Division Meetings.
• Type: Other Status: Published Year Published: 2017 Citation: Dyer, A., Johnston, J., Tharp, C., Rupp, J., Lane, T., Fulbright, J., Small Grain Treatment Guide. Montguide: MT199608AG 11/17. 8p.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Growers, Agriculturalists, Agricultural Scientists, Microbiologists, Pathologists, and Ecologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This program has trained two graduate students and is currently training an additional three graduate students. This year, theprinciple investigatorformally taught 40 undergraduate students, many of which will be future farmers and ranchers in Montana. How have the results been disseminated to communities of interest?A presentation was made at Montana Grain Growers meeting.The principle investigator regularlytroubleshoots questions directly from growers through site visits, emails and phones calls.In the previous year, an extension guide was published on assessment and management of root lesion nematodes to inform growers within Montana about how to manage this growing threat. This year that information along with more comprehensive scientific data was published in the journal "Plant Disease" which will disseminate this information nationally to nematologist and other cereal pathologist. What do you plan to do during the next reporting period to accomplish the goals?Progress will continue along all three objectives with efforts to provide advanced field performance testing of winter and spring wheat lines, toincrease our understanding of integrated control measures and toexplain the ecology and evolution of root pathogens in complex microbial communities.

Impacts
What was accomplished under these goals? Advanced winter wheat lines are being tested for resistance to root lesion nematodes, Fusarium crown rot and Cephalosporium stripe. Additional lines are being advanced and tested in spring wheat and winter wheat for resistance to root lesion nematodes, Fusarium crown rot, Cephalosporium stripe, and powdery mildew. Research is ongoing in understanding thedynamics control practices impose on disease systems across successive years andunderstanding the variability of responses among populations of pest species. For the latter, particular emphasis is on Pratylenchus neglectus, the root lesion nematode and variability in virulences displayed by its populations throughoutMontana. Finally, our program has identified new competitive interactions between root rot fungi and have made strides in empirically modeling impacts complex pathogen communities have onplant health. These cutting edge developmentsare expected tobroadly impact not onlythe field of plant pathology but also the more fundmentalstudies of microbial ecology.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: May, D.B., Johnson, W.A., Zuck, P.C., Chen, C.C. and Dyer, A.T. 2016. Assessment and Management of Root Lesion Nematodes in Montana Wheat Production. Plant Dis. 100:2069-2079.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Gunnink Troth, E., Johnston, J., Dyer, A., 2016 Impacts on plant health of complex pathogen communities. Proceeding of Pacific Division Meeting of the American Phytopathological Society pg 32.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Gunnink Troth, E., Johnston, J., Dyer, A. 2016. Impacts of complex root pathogen communities on plant health. 16th International Symposia on Microbial Ecology, ISME

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Growers, Agriculturalistsand Agricultural Scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?In addition totraining for three graduate students and numerous undergraduates, our program has hosted an Advanced Diagnostic Workshop for agriculturalists in Montana, and presented at a growers meeting on the recent discovery ofcereal cyst nematodes in Montana. How have the results been disseminated to communities of interest?We have made presentations to all stakeholders in the current year; scientists, agriculturalists, and growers. What do you plan to do during the next reporting period to accomplish the goals?Besides the advancement of breeding lines and the integration of new disease control measures, our laboratory intends to explore the mechanisms of pathogen on pathogen interactions. Some of these characters appear to coincide with pathogen aggressiveness and may not only provide insights into ecological control but also into plant pathogen-interactions.

Impacts
What was accomplished under these goals? Objective 1: Incorporation ofresistance in elite wheat lines was soughtforroot lesion nematode (Pratylenchus neglectus), Fusarium crown rot, and Cephalosporium stripe. Resistance to root lesion nematode has beenincorporated into elite winter wheat lines. In intial trials,our root lesion nematodelines displayed superior yield and acceptable grain quality, but were too tall for release. Two of thelines were chosen for additional crosses and selection. With regards to Fusarium crown rot resistance, advanced winter wheat lines are currently being evaluated in the field for performance while spring wheat lines are currently being evaluated for disease resistance in greenhouse assays. Resistance to Cephalosporium stripe is in early stages ofdevelopment and screening. Unexpected problems with powdery mildew has resulted in the addition of this disease to the program with segregating populations being currently screened forresistance. Objective 2: Trials are underway to incorporate advances in Fusarium crown rot resistance and seed treatment fungicides into intregrated management recommendations for this disease within Montana. Objective 3: Preliminary trialsstudying how 5 soilborne wheat pathogens interact in the field have been successfully completed with results being prepared for publication in 2016. Variation within pathogen populations have also been explored, resultsexplain variations in responses described inprevious literature.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: A. T. Dyer, R. Al-Khafaji, T. Lane, T. Paulitz, Z. A. Handoo, A. M. Skantar, and D. J. Chitwood. 2015. First Report of the Cereal Cyst Nematode Heterodera filipjevi on Winter Wheat in Montana. Plant Disease 99:1188.
• Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: D.B. May. 2015 Breeding for root lesion nematode resistance in Montana winter wheat Thesis: http://scholarworks.montana.edu/xmlui/handle/1/8863
• Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Gunnink Troth, E. 2015. Population dynamics of coexistence by plant pathogens of the rhizosphere of spring wheat, 145pp.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Gunnink Troth, E., Johnston, J., Dyer A. 2015. The population dynamics of coexistence between Cochliobolus sativus and Fusarium pseudograminearum in wheat. Phytopathology 105(Suppl. 4):S4.54