IDENTIFICATION, BIOLOGY, AND MANAGEMENT OF AGRICULTURALLY IMPORTANT PLANT PARASITIC NEMATODES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0221022
• Project No.: LAB94025
• Project Start Date: Oct 1, 2009
• Project End Date: Sep 30, 2014

Project Director
Mcgawley, E.

Recipient Organization
LOUISIANA STATE UNIVERSITY
202 HIMES HALL
BATON ROUGE,LA 70803-0100

Performing Department
Plant Pathology & Crop Physiol

Non Technical Summary
Plant parasitic nematodes are a serious, ever-present and insidious agricultural production constraint. They are the most biologically complex of the classical plant pathogen types. They are frequently overlooked because most reside in the soil as root parasites and the damage they cause is frequently attributed to non-biological entities such as water-logging, drought or nutrient deficiencies or toxicity. By virtue of their metabolic complexity, the chemicals used to manage them have historically been the most toxic. The environmental consequences of overuse and mishandling of many of these chemicals have resulted in their ban by the U.S. EPA in recent years. In the near future, a majority of the remaining nematicide arsenal will like be banned. It is for this reason that we are allocating a significant portion of our activities toward the identification of new materials and organisms which can efficiently manage/suppress nematode pathogens with minimal environmental consequences.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
212	1122	1120	10%
216	1460	1120	10%
212	1411	1120	10%
212	1530	1120	10%
212	1710	1120	10%
216	1820	1120	10%
212	2020	1120	10%
212	3130	1120	30%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 216 - Integrated Pest Management Systems;

Subject Of Investigation
1411 - Beans (fresh, fresh-processed); 3130 - Nematodes; 1122 - Strawberry; 2020 - Sugar cane; 1460 - Tomato; 1710 - Upland cotton; 1820 - Soybean; 1530 - Rice;

Field Of Science
1120 - Nematology;

Keywords

nematode pathogens, nematode management, novel management techniques,

nematode pathotypes, nematode complexes

Goals / Objectives
(1) To identify genera, species, and races of plant parasitic nematodes that impact crop species important in agriculture in Louisiana. (2) To evaluate the interrelationship of plant parasitic nematodes with other organisms present in agricultural production systems in Louisiana. (3) To evaluate environmentally responsible management tactics useful in minimizing nematode-related crop losses.

Project Methods
The maintenance of a current census of nematode genera, species, and pathotypes associated with the major crop commodities of Louisiana is one of three objectives of this project. Soil and root samples representative of the major crops and production areas in the state are collected. Laboratory activities include extraction and microscopic enumeration, for generic identification. Known damaging genera are further identified by being subjected to electrophoretic analysis of macerated preparations of the females that produce diagnostic banding patterns on acrylamide gel. Other genera which require speciation are subjected to greenhouse-based host range assays. The second project objective, to evaluate the interrelationship of plant parasitic nematodes with other organisms present in agricultural production systems in Louisiana, is addressed primarily by using microplot (autoclaved terra cotta containers [arranged in an outside, covered environment] containing "biologically clean" soil which is infested with known pathogen or pathogen/pesticide combinations)-based methodology. This protocol, which mimics a production environment, allows precise manipulation of pathogen population combinations and/or chemicals being evaluated for their management. The third objective of this project is to evaluate environmentally responsible management tactics useful in minimizing nematode-related losses. Currently this research is focused primarily on the identification and evaluation of new, low-rate, chemical nematicides. Studies will involve field plot and microplot evaluations of two colloid based materials, one biological agent and leachates collected from three weed species common in Louisiana. Results of this research are presented first hand to producer groups and forwarded to our extension nematologist for further dissemination. Research data from all of these studies is subjected to appropriate scientific data analysis protocols and summarized in an annual report.

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

Outputs
Target Audience: Target audiences include major crop producers in Louisiana, chemical company representatives, and other plant pathologists, nematologists, and students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? These projects have provided training forthree graduate students andfour undergraduate students who have assisted with research. The project has also provided E.C. McGawley with experience in the new classes of environmentally-responsible, low rate nematicides. Also, experience with regulations and protocols necessary to conduct research with genetically modified plants has been valuable. How have the results been disseminated to communities of interest? The research data has been reviewed in refereed and producer-level publications. Additionally, E.C. McGawley has attended national and international meetings, symposia and conferences at the rate of 4-5 per year to make oral presentations of current research data. Much of this information also is in online resources. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Accomplishments for Goal 1. a) Identified and demonstrated reproductive and pathogenic variation in populations of the reniform nematode, Rotylenchulus reniformis, on cotton and soybean. b) Identified and demonstrated first report of pathogenicity of the lesion nematode, Pratylenchus zeae and Meloidogyne incognita on St. Augestine and Centipede grasses. Accomplishment for Goal 2. a) Described and published results to show that certain weed species produce anti-helminthic products. Also submitted grant proposal to USDA to further explore this nematode and weed relationship. Accomplishments for Goal 3. b) Have conducted cooperative research withfour major agri-chemical companies to evaluate fungal metabolites, bacterial hyperparasites of nematodes, genetically modified plants and seed treatments for efficacy against soybean cyst, root-knot and reniform nematodes

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Xavier, D. M., C. Overstreet, E. C. McGawley, M. T. Kularathna, and C. M. Martin. 2013. The influence of soil texture on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Nematropica 44:7-14.
• Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Overstreet, C., E. C. McGawley, A. Khalilian, T. L. Kirkpatrick, W. S. Monfort, W. Henderson, and J. D. Mueller. 2014. Site specific nematode management- development and success in cotton production in the U.S. Journal of Nematology, in press
• Type: Journal Articles Status: Submitted Year Published: 2014 Citation: Plaisance, A. R., E. C. McGawley, and C. Overstreet. 2014. Species abundance and influence of nematodes in urban turfgrass ecosystems in East Baton Rouge Parish, LA. Nematropica 44.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Kularathna, M. T., C. Overstreet, E. C. McGawley, D. M. Xavier, and C. M. Martin. 2014. Influence of soil nutrients on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Nematropica 44:15-24.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Audiences include major crop producers in Louisiana, chemical company representatives, and other plant pathologists, nematologists, and students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Presentations at five professional meetings have provided current information to producers, colleagues and students in nematology. How have the results been disseminated to communities of interest? Oral and written formats. What do you plan to do during the next reporting period to accomplish the goals? Additional studies will be conducted with pinewood nematode to further document its distribution in Louisiana and evaluate the influence of Japanese and American pine sawyer beetle vectors on dissemination. Research with reniform nematode will continue. Field and microplot studies are planned in cooperation with several commercial interests to evaluate new biological control agents against reniform and root-knot nematodes.

Impacts
What was accomplished under these goals? Field research with reniform nematode highlighted the potential for site-specific nematologyto improve cotton yields in the southern United States. Greenhouse research with reniform nematodeillustrated the importance of soil fertility and texture in the pathology of this nematode on cotton. Pinewood nematode surveysdocumented the current levels of infestationin Louisiana'sindigenous pine species. Laboratory studies investigate the role of various life stages of the nematode in explaining differences in pathology among geographical isolates.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Kularathna, M. T., C. Overstreet, E. C. McGawley, D. M. Xavier, C. M. Martin, and D. Burns. 2013. Influence of soil nutrients on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Proceedings of the Beltwide Cotton Conference, 7-10 January 2013; San Antonio, TX. National Cotton Council, Cordova, TN. Pp. 477-483.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Overstreet, C., E. C. McGawley, M. T. Kularathna, D. M. Xavier, C. M. Martin, D. Burns, and R. A. Haygood. 2013. Nutient and nematicide effects against reniform and root-knot nematodes in cotton. Proceedings of the Beltwide Cotton Conference, 7-10 January 2013; San Antonio, TX. National Cotton Council, Cordova, TN. Pp. 906-910.
• Type: Books Status: Published Year Published: 2013 Citation: Xavier, D. M., C. Overstreet, E. C. McGawley, M. T. Kularathna and C. M. Martin. 2013. Influence of soil texture on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Proceedings of the Beltwide Cotton Conference, 7-10 January 2013; San Antonio, TX. National Cotton Council, Cordova, TN. Pp. 460-464.
• Type: Conference Papers and Presentations Status: Submitted Year Published: 2013 Citation: Overstreet, C., E. C. McGawley, and D. M. Xavier. 2013. The role of extension nematology in the United States. Nematropica (in press).
• Type: Conference Papers and Presentations Status: Submitted Year Published: 2013 Citation: Xavier, D. M., C. Overstreet, E. C. McGawley, M. J. Kularathna, D. Burns, R. L. Frazier, and C. M. Martin. 2013. Effect of commerce silt loam soil texture on population development of Rotylenchulus reniformis. Nematropica (in press).
• Type: Conference Papers and Presentations Status: Submitted Year Published: 2013 Citation: Takeuchi, Y., E. C. McGawley, and C. Overstreet. 2013. Comparison of Japanese and American isolates of the pinewood nematode, Bursaphelenchus xylophilus. Journal of Nematology (in press).

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Research presentations were delivered at the annual meetings of the Society of Nematologists, the European Society of Nematologists, the Southern Regional Research Project S-1046, the 6th SETAC World Congress and the Beltwide Cotton Meetings. Invited oral presentations were also made at Sakata Seed Company Headquarters and at the Syngenta Nematology Conference. This research resulted in five publications, and significant progress toward an MS degree. PARTICIPANTS: E.C. McGawley (PI), C. Overstreet, A. Plaisance, D. Xavier, M. Kularathna, LSU AgCenter. TARGET AUDIENCES: Louisiana agricultural producers, nematologists and plant pathologists and students in these disciplines and agrichemical industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Educational materials were included on the leading nematology websites (nematology.org; ontaweb.org; esn-online.org and nematology.net) in the world, and available for free download in five different languages with two more being added in 2013. The research documents, for the first time in Louisiana, the abundance and spectrum of nematodes in urban turf ecosystems. Other field research with reniform nematode outlines strategies for site specific nematode management, a practice that can significantly reduce nematicide usage and subsequent environmental consequences while still minimizing nematode damage from reniform and root knot nematodes.

Publications

• Overstreet, C., E. C. McGawley, D. Burns, R. L. Frazier, and R. Barbosa. 2012. The influence of apparent electrical conductivity of the soil on nematicides in cotton. Beltwide Cotton Proceedings, pages 288-292.
• Overstreet, C., E. C. McGawley, D. Xavier, M. Kularathna, M. Martin, D. Burns and R. L. Frazier. 2012. Site-specific technology to better manage nematodes in cotton. Proceedings of the 7th National IPM Symposium, Pp. 88-89.
• Overstreet, C., E. C. McGawley, D. Xavier, M. Kularathna, and M. Martin. 2012. Nematicide effects on Meloidogyne incognita and Rotylenchulus reniformis in cotton fields with variable soil texture. Journal of Nematology. In Press

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: A graduate level course was taught in Plant Nematology with 11 students and served as major professor for one student conducting a survey of nematodes associated with residential turf ecosystems. I also served as a committee member for four graduate students (one as major advisor) conducting research with nematodes important in Lousiana agriculture. A keynote presentation was delivered at the annual meeting of Society of Nematologists during a visit to the Terrestrial Microbial Ecology laboratory of the Division of Environmental Science and Technology at Kyoto University in Japan. Services with a small company, CAI, in North Carolina supported registration thru an IR-4 Project of a promising new material (Agri-Trap) for the management of plant parasitic nematodes. A major section on "Molecular Diagnostics" was added to an on-line multimedia production entitled, "Introduction to Nematodes." Collaboration with Japanese scientists has helped to establish a screening method to detect reniform nematode in soybean and to quantify virulence phenotypes. PARTICIPANTS: E.C. McGawley (PI), LSU AgCenter. TARGET AUDIENCES: Nematologists, plant protection practitioners, and agric. industries. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Field research evaluated the efficacy of eight new nematicide seed-treatments against root-knot nematode. Microplot and greenhouse-based experiments evaluated genetically modified soybean for resistance to soybean cyst and reniform nematodes, respectively. Seed treatment evaluation studies have shown that only two materials are effective against the most common species of root-knot nematode, Meloidogyne incognita, found in Louisiana. Results of microplot and greenhouse studies with the genetically modified soybean events, products of Bayer CropScience, are very encouraging and showed that these modified genotypes do inhibit cyst and reniform nematode reproduction via an introduced protein secreted by the root systems. If commercialized, such introductions will allow for production in nematode infested fields with minimal if any nematicide usage. Results of these studies have identified promising new materials for the management of root knot nematode and evaluated genetically modified soybean plants to withstand parasitism by the soybean cyst and reniform nematodes.

Publications

• McGawley, E. C., C. Overstreet and M. J. Pontif. 2011. Variation in reproduction and pathogenicity of geographic isolates of Rotylenchulus reniformis on soybean. Nematropica 41:12-22.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Research describing the existence of virulence phenotypes of the reniform nematode, Rotylenchulus reniformis, on cotton was published. In two other publications, research on the use of site-specific management practices for reniform nematode was outlined. A multimedia presentation entitled, "Introduction to Nematodes" was released via the internet site of the Organization of Nematologists of Tropical America (ontaweb.org) in 2010. During this reporting period, a graduate level class in nematology was taught. National and international plant pathology and nematology meetings, at which multiple research and teaching presentations were made, were also attended. PARTICIPANTS: Drs. Charles Overstreet and Michael J. Pontif are collaborators on this project. TARGET AUDIENCES: Target audiences are plant breeders, soybean and cotton producers and plant protection scientists. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The "Introduction to Nematodes" presentation has had over 1000 downloads to date and has received favorable reviews on the websites of the European Society of Nematologists, The Mediterranean Society of Plant Pathology and the International Federation of Nematology Societies. Data generated by this project strongly supports the hypothesis that virulence phenotypes of Rotylenchulus reniformis exist in the southern United States. This research is the first in the United States to clearly document this difference in pathogenicity among geographic isolates of the nematode and partially accounts for the difficulty in producing resistant cotton germplasm.

Publications

• McGawley, E. C., M. J. Pontif, and C. Overstreet. 2010. Variation in reproduction and pathogenicity of geographic Isolates of Rotylenchulus reniformis on cotton. Nematropica 40:275-288.
• McGawley, E. C., M. J. Pontif, and C. Overstreet. 2010. Introduction to Nematodes: a Multimedia presentation.
• Overstreet, C., E.C. McGawley, E. Burris, D. Burns, B. Padgett and R.L. Frazier. 2010. Site-specific management strategies used in Louisiana. Pg. 52-59 In: Proceedings of the Beltwide Cotton Conferences, New Orleans, LA.
• Overstreet, C., E. C. McGawley, M. Wolcott, D. Burns, E. Burris, and G. B. Padgett. 2010. Using verification strips to define nematicide response areas to the Southern root-knot and reniform nematodes in cotton in the Alluvial soils of the mid-South, USA. Pg. 144. In: Proceedings of the 3rd Conference on Precision Crop Protection. Bonn, Germany.