CHARACTERIZATION OF PHENOTYPIC, GENETIC, AND MOLECULAR DIVERSITY OF PLANT PATHOGENIC FUNGI

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0190962
• Project Start Date: Oct 1, 2007
• Project End Date: Sep 30, 2012
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF ARKANSAS
(N/A)
FAYETTEVILLE,AR 72703

Performing Department
Plant Pathology

Non Technical Summary
Genetic diversity of several species and populations of economically important plant pathogenic fungi will be examined. The identification of genetic groups will help facilitate screening for disease resistance to these pathogens in a number of agricultural crops.

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	4020	1080	100%

Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
4020 - Fungi;

Field Of Science
1080 - Genetics;

Keywords

population diversity

molecular markers

Goals / Objectives
The overall goal of the project is to examine the inter and intra specific phyogenetic variation of several key plant pathogenic fungi using phenotypic, gentic, and molecular markers following a phylogenic species concept approach. Specific obectives are to (1) Characterize the diversity of the rice blast pathogen, Magnaporthe oryzae, using virulence, vegetative compatibility, DNA fingerprinting (MGR586), and newly developed microsatellite markers; and (2) Examine phylogenetic relationships both within and between various species of Colletotrichum Fusarium, and Peronospora using genetic and molecular markers.

Project Methods
Populations of several species of Colletotrichum (C. orbculare, C. lindemuthianum, C. trifollii, C. gloeosporioides, C. acutatum,), Fusarium oxysporum f. sp. spinaciae and F. oxysporum f. sp. lycopersici,Pyricularia oryzae and Personosproa farinose f. sp. spinaciae will be examined for genetic and molecular variation. A range of genetic and molecular markers have been developed and employed to characterize the various plant pathogens. Efforts will continue to develop useful and more powerful molecular techniques for characterizing inter- and intra- species diversity along with population diversity of several important plant pathogenic fungal species. Cultures of the various pathogens have been collected from throughout the world and stored in our culture collection. Efforts continue to expand these collections to be fully representative of the genetic and geographic diversity present in a given population. Efforts have also included hierarchical sampling, particularly with the rice blast pathogen, P. oryzae. A wide range of genetic and molecular markers have been developed and utilized in our laboratory to examine intra- and inter- species variation. These markers have included color, nitrate and sulfate non-utilizing mutations, vegetative incompatibility loci, mating alleles, mtDNA RFLPs, RAPDs, nuclear DNA fingerpriting, AFLPS, and RFLPs and sequencing of intron variation from several genes. In addition, virulence phenotypes have been determined among a wide rage of molecular genotypes. In addition, sequencing of a number of highly informative nuclear genes will be conducted for comparison. A considerable effort focuses on the sexual mating potential of P. grisea and Colletotrichum species. Molecular mating types have been determined in contemporary populations of the rice blast pathogen. Also, functional mating populations are being characterized in C. acutatum. A newly described teleomorph (Glomerella acutata) has been described based on sexual reproduction studies with C. acutatum.

Progress 10/01/07 to 09/30/12

Outputs
OUTPUTS: We continue to evaluate several plant pathogenic fungi including the rice blast pathogen, Magnaporthe oryzae, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum, and Verticillium spp. for genetic diversity. Several new genotypes and species of Colletotrichum have been collected and characterized in 2012 and their molecular diversity is being characterized. In addtion, some robust moleclar SSR markers have been developed for characterizing diversity of the rice blast pathogen. Pathogens are being examined for virulence diversity and molecular diversity at the mitochondrial and genomic levels. Also, sexual and vegetative compatibility are being examined in several species of Colletotrichum, Magnaporthe oryzae, and Fusarium oxysporum. Efforts have also focused on the pathogenic and molecular diversity of Verticillium from spinach. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
A wide reange of isolates of V. dahliae from a wide range of hosts and geographic origins were evaluated for their pathogenicity and virulence on spinach. Indications are that there is some level of host specificity being observed. Several species from spinach, including Verticillium tricorus and Gibellulopsis nigrescens have been shown to be non-pathogenic on spinach. In contrast, a wide range of virulence diversity has been found among isolates of V. dahliae on spinach. We have also collected and genetically characterized a wide range of isolates of Rhizoctonia solani for phenotypic and genotypic diversity.

Publications

• Bo, Liu, Louws, F. J., and Sutton, T. B. 2012. A rapid qualitative molecular method for the identification of Colletotrichum acutatum and C. gloeosporioides. Eur. J. of Plant Path. DOI 10.1007/s10658-011-9904-1.
• Rodriguez-Salamanca, L.M., Enzenbacher, T. B., Derie, M., du Toit, L. J., Feng, C., Correll, J. C., and Hausbeck, M. K. 2012. First report of Colletotrichum coccodes causing leaf and neck anthracnose on onions (Allium cepa) in Michigan. Plant Disease 96:1383.
• Swain, S.V., Koike, S. T., Michailides, T. J., Feng, C. and Correll, J. C. 2012. First report of Colletotrichum acutatum on willow in California. Plant Disease 96:1822.
• Liu, G., Y. Jia, A. McClung, J. Oard, F. Lee, and J. C. Correll. 2013 Confirming QTLs and finding additional loci responsible for resistance to rice sheath blight disease. Plant Disease 97:113-117.
• Geiser, D. M, et al 2013. One fungus, one name: Defining the genus Fusarium in a scientifically robust way that preserves longstanding use. Phytopathology 103: (in press).
• Feng, C., Rotich, F. and Correll, J. C. 2012. Disease reactions of IRRI near-isogenic rice to U.S. isolates of Magnaporthe oryzae. Phytopathology 102.
• Jia, Y., Zhang, Z., Xing, J., Wang, Y., Correll, J. C., and Cartwright, R. D. 2012. Natural variation and evolution of the avirulence genes in Magnaporthe oryzae. Phyopathology 102.

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

Outputs
OUTPUTS: We continue to evaluate several plant pathogenic fungi including the rice blast pathogen, Magnaporthe oryzae, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum, and Verticillium spp. for genetic diversity. Several new genotypes and species of Colletotrichum have been collected in 2011 and their molecular diversity is being characterized. In addtion, some robust moleclar SSR markers have been developed for characterizing diversity of the rice blast pathogen. Pathogens are being examined for virulnce diversity and molecular diversity at the mitochondrial and genomic levels. Also, sexual and vegetative compatibility are being examined in several species of Colletotrichum, Magnaporthe oryzae, and Fusarium oxysporum. Efforts have focused on the pathogenic and molecular diversity of Verticillium from spinach. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Isolates of V. dahliae from a wide range of hosts and geographic origins are being evaluated for their pathogenicity and virulence on spinach. Indications are that there is some level of host specificity being observed. Several species from spinach, including Verticillium tricorus and Gibellulopsis nigrescens have been shown to be non-pathogenic on spinach. In contrast, a wide range of virulence diversity has been found among isolates of V. dahliae on spinach.

Publications

• du Toit, L. J., Derie, M. L., Holmes, B. J., and Correll, J. C. 2011. Effect of seed treatments and soil fumigation on seed transmission and soil infestation by Verticillium in a baby leaf spinach head lettuce rotation. International Spinach Conference, Amsterdam, Netherlands.
• Iglesias-Garcia, A., Feng, C., duToit, L. J., and Correll, J. C. 2011. Pathogenicity, virulence, and molecular characterization of Verticillium Species from spinach and other hosts. International Spinach Conference, Amsterdam, Netherlands.

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

Outputs
OUTPUTS: We continue to evaluate several plant pathogenic fungi including the rice blast pathogen, Magnaporthe oryzae, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum, and Verticillium spp. for genetic diversity. Several new genotypes and species of Colletotrichum have been collected in 2010 and their molecular diversity is being characterized. In addtion, some robust moleclar SSR markers have been developed for characterizing diversity of the rice blast pathogen. Pathogens are being examined for virulnce diversity and molecular diversity at the mitochondrial and genomic levels. Also, sexual and vegetative compatibility are being examined in several species of Colletotrichum, Magnaporthe oryzae, and Fusarium oxysporum. Efforts have focused on the pathogenic and molecular diversity of Verticillium from spinach. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Isolates of V. dahliae from a wide range of hosts and geographic origins are being evaluated for their pathogenicity and virulence on spinach. Indications are that there is some level of host specificity being observed. Several species from spinach, including Verticillium tricorus and Gibellulopsis nigrescens have been shown to be non-pathogenic on spinach. In contrast, a wide range of virulence diversity has been found among isolates of V. dahliae on spinach.

Publications

• Dai, Y., Jia, Y., Correll, J. C., Wang, X., and Wang, Y. 2010. Diversification and evolution of the avirulence gene AVR-Pita in field isolates of Magnaporthe oryzae. Fungal Genetics and Biology 47:973-980.
• Oard, J. H., Moldenhauer, K., Fjellstrom, B., Nelson, J. C., Scheffler, B., Linscombe, S. Correll, J. C., Silva, J., and May, G. D. 2010. Registraction of the MY2 Cypress/LaGrue rice recombinant inbred line mapping population. Journal of Plant registrations 4:1-5. Doi: 10.3198/jpr2009.11.0668crmp
• Castroaguidin, V. L., Cartwright, R. D., and Correll, J. C. 2010. Multilocus analysis of Rhizoctonia solani and related species associated with rice sheath blight in Arkansas. Phytopathology 100:S22.
• Zhai, L. Feng, C., Cartwright, R. D., and Correll, J. C. 2010. Genotypic and phenotypic diversity of Pyricularia oryzae in the contemporary rice blast pathogen population in Arkansas. Phytopathology 100:S145.
• Welch, K. D., Correll, J. C., and Gavin, J. C. 2010. Rice grafting as a disease management tool for Fusarium wilt of heirloom tomatoes in Arkansas. Phytopathology 100:S135.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: We continue to evaluate several plant pathogenic fungi including the rice blast pathogen, Magnaporthe oryzae, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum, and Verticillium spp. for genetic diversity. Pathogens are being examined for virulnce diversity and molecular diversity at the mitochondrial and genomic levels. Also, sexual and vegetative compatibility are being examined in several species of Colletotrichum, Magnaporthe oryzae, and Fusarium oxysporum. Efforts have focused on the pathogenic and molecular diversity of Verticillium from spinach. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Isolates of V. dahliae from a wide range of hosts and geographic origins are being evaluated for their pathogenicity and virulence on spinach. Indications are that there is some level of host specificity being observed.

Publications

• Liu, G., Jia, Y., Correa-Victoria,F.J., Prado, G.A., McClung, A., and Correll, J.C. 2009. Mapping quantitative Trait Loci responsible for resistance to rice sheath blight disease using greenhouse methods. Phytopathology 99:1078-1084.
• Castroagudin, V. L., Correll, J. C., and Cartwright. R. D. 2009. First report of fruit rot of pumpkin caused by Fusarium solani f. sp. cucurbitae in Arkansas. Plant Disease 93:669.
• Koike, S. T., Fake, C. E., and Correll, J. C. 2009. Anthracnose of sunflower sprouts caused by Colletotrichum acutatum in California. Plant Disease 93: 1351.
• Correll, J. C., Boza, E. J., Seyran, E., Cartwright, R. D., Jia, Y., and Lee, F. N. 2009. Eds. G. Wang. Examination of the rice blast pathogen population diversity in Arkansas, USA - stable or unstable Advances in the genetics genomics, and control of rice blast disease. Pgs 217-228. Springer.
• Lee, F. N., Cartwright, R. D., Jia, Y., and Correll, J. C. 2009. Field resistance expressed when the Pi-ta gene is compromised by Magnaporthe oryzae. Advances in the genetics genomics, and control of rice blast disease. In: G.-L. Wang and B. Valent (eds.), Advances in Genetics, Genomics and Control of Rice Blast Disease. Springer. Pgs 281-289.
• Castroaguidin, V. L., Cartwright, R. D., and Correll, J.C. 2009. Biological diversity, pathogenicity and population structure of Rhizoctonia spp. associated with rice sheath blight in Arkansas. Phytopathology 99:S19.
• Dai, Y. Jia, Y., and Correll, J. C. 2009. Structural and functional analysis of the avirulence gene AVR-Pita1 of the rice blast fungus in isolates of Magnaporthe oryzae worldwide. XVII Plant and Animal Genomics Meeting. San Diego, CA. Jan 12.
• Correll, J. C. 2009. RiceCAP: A coordinated research, education, and extension project for the application of genomic discoveries to improve rice in the United States. XVII Plant and Animal Genomics Meeting. San Diego, CA. Jan. 12.
• Correll, J. C. 2009. RiceCAP: A coordinated research, education, and extension project for the application of genomic discoveries to improve rice in the United States. XVII Plant and Animal Genomics Meeting. San Diego, CA. Jan. 12.
• Correll, J. C. 2009. An overview of progress on the first CSREES supported Plant Coordinated Project. RiceCAP:American Society of Agronomy Annual Mtg Nov. 2009.
• McClung, A. M. et al. 2009. RiceCAP: Progress in identifying QTL for sheath blight resistance and milling yield. American Society of Agronomy Annual Mtg Nov. 2009.
• Correll, J. C., Jia, Y. Cartwright, R. C., and Lee, F. N. 2010. Rice blast in the U.S. - more than a model. Plant and Animal Genomes XVIII.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Several plant pathogenic fungi including the rice blast pathogen, Magnaporthe oryzae, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum, and Verticillium spp. are being examined for their genetic diversity. Also, virulence evolution is being examined in Magnaporthe grisea by evaluating virulence phenotype changes and by monitoring the variation in avirulence genes. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum. PARTICIPANTS: Two distinct vegetative compatibility groups have been identified among a large globally distributed group of isolates from spinach seed. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Significant progress has been made in characterizing a global population of isolates of Colletotrichum acutatum from pepper and Verticillium dahliae from spinach and Verticillium spp. from several hosts using a wide range of morphological, genetic, and molecular markers. The markers used were robust at teh species and subspecies level

Publications

• Dai, Y., Jia, Y., Wang, Y. Lee, F. N., and Correll, J. C. 2008. Structural and functional analysis of the rice blast fungus avirulence gene AVR-Pita. Phytopathology 98:S44.
• Feng, C., Ware, S. B., Cornelius, K., Gabor, B., Harp, T. L., and Correll, J. C. 2008. Examination of variation among isolates of Colletotrichum species causing chili anthracnose worldwide. Phytopathology 98:S53.
• Liu, G., Jia, Y., Correa-Victoria, F. J., McClung, A. and Correll, J. C. 2008. Identification of quantitative trait loci (QTLs) responsible for sheath blight resistance in rice using recombinant inbred line populations of Lemont x Jasmine 85. Phytopathology 98:S92.
• Villarroel-Zeballos, M. I., du Toit, L. J., and Correll, J. C. 2008. Screening for disease resistance to Verticillium dahliae in spinach. Phytopathology 98 :S163.
• Correll, J. C., du Toit, L. J., and Villarroel-Zeballos, M. 2008. Verticlillium wilt and seed transmission. International Spinach Conference. San Antonio, TX. Dec. 1.
• Correll, J. C. Koike, S. Feng, C., and Morelock, T.E. 2008. Update on spinach downy mildew in Arkansas and California. International Spinach Meeting. San Antonio, TX. Dec 1.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Several plant pathogenic fungi including the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum are being examined for their genetic diversity. Also, virulence evolution is being examined in Magnaporthe grisea by evaluating virulence phenotype changes and by monitoring the variation in avirulence genes. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum. PARTICIPANTS: JAmes Correll

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important in the movement of international agricultural commerce. A great deal is unknown with regard to the inter- and intra-species relationships of these economically important plant pathogens. Virulence phenotyping of fungal pathogens is critical to efforts to screen for disease resistance.

Publications

• Bo, L., Wasilwa, L. A., Guerber, J. C. , Morelock, T. E., ONeill, N. R., and Correll, J. C. 2007. Comparison of Colletotrichum orbiculare and allied Colletotrichum species for mtDNA RFLPs, intron RFLPs, sequence variation, vegetative compatibility, and host specificity. Phytopathology 97:1305-1314.
• Timila, R. D., Correll, J. C., and Duwadi, V. R. 2008. Severe and widespread clubroot epidemics in Nepal. Plant Disease 92:

Progress 01/01/06 to 12/31/06

Outputs
Several plant pathogenic fungi including the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum are being examined for their genetic diversity. Also, virulence evolution is being examined in Magnaporthe grisea by evaluating virulence phenotype changes and by monitoring the variation in avirulence genes. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum.

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important in the movement of international agricultural commerce. A great deal is unknown with regard to the inter- and intra-species relationships of these economically important plant pathogens. Virulence phenotyping of fungal pathogens is critical to efforts to screen for disease resistance.

Publications

• Gonzalez, E., Sutton, T. B., and Correll, J. C. 2006. Clarification of the etiology of Glomerella leaf spot and bitter rot of apple caused by Colletotrichum spp. Based on morphology and genetic, molecular, and pathogenicity tests. Phytopathology 96:982-992.
• Jia, Y. Correa-Victoria, F., McClung, A., Zhu, L., Liu, G., Wamishe, Y., Xie, J., Marchetti, M.A., Pinson, S. R. M., Rutger, J. N., and Correll, J. C. 2007. Rapid determination of rice cultivar responses to the sheath blight pathogen Rhizoctonia solani using a micro-chamber screening method. Plant Disease (accepted).
• Zhou, E, Jia, Y. Singh, P, Correll, J. C., and Lee, F. N. 2007. Instability of the Magnaporthe oryzae avirulence gene AVR-Pita alters virulence. Fungal Genetics and Biology (accepted).
• Bo, L., Wasilwa, L. A., Guerber, J. C. , Morelock, T. E., ONeill, N. R., and Correll, J. C. 2007. Comparison of Colletotrichum orbiculare and allied Colletotrichum species for mtDNA RFLPs,intron RFLPs, sequence variation, vegetative compatibility, and host specificity. Phytopathology 97: (submitted).

Progress 01/01/05 to 12/31/05

Outputs
Several plant pathogenic fungi including the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum are being examined for their genetic diversity. Also, virulence evolution is being examined in Magnaporthe grisea by evaluating virulence phenotype changes and by monitoring the variation in avirulence genes. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum.

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important in the movement of international agricultural commerce. A great deal is unknown with regard to the inter- and intra-species relationships of these economically important plant pathogens.

Publications

• Correll, J. C., Villarroel, M. I., McLeod, P. J., Cazon, M. I., and Rivadeneria, C. 2005. First Report of Powdery Mildew Caused by Leveillula taurica on Tomato and Pepper in Bolivia. Plant Disease 89:776.
• Peres, N. A., Timmer, L. W., Adaskaveg, J. E., and Correll, J. C. 2005. Lifestyles of Colletotrichum acutatum. Plant Disease 89:784-796.
• Ouedraogo, I., Correll, J. C., Boza, E. J., Cartwright, R. D., and Lee, F. N. 2005. Examination of the brown spot and eye spot pathogens of rice and related fungi. Arkansas Rice Research Series.
• Jia, Y., Zhou, E., Winston, E., Singh, P. Correll, J. C., Lee, F. N., and Valent, B. 2005. Molecular Co-evolution of the Rice Pi-ta Resistance Gene and Magnaporthe grisea Avirulence Gene AVR-Pita (submitted).
• McLeod, P., M.E. Pontaroli, J.C. Correll, F. Copa, H. Serrate and R. Unterladstaetter. 2005. Identificacion y Manejo de Insectos en Hortalizas en Bolivia (Identification and Management of Vegetable Insects in Bolivia). Sirena Press, Santa Cruz, Bolivia. 163 pp.
• Lee, F. N., Cartwright, R. D., Jia, Y. and Correll, J. C. 2005. Magnaporthe grisea race shift for virulence to the major R gene, Pi-ta in Arkansas. Phytopathology 95: S175.
• Correll, J. C., Koike, S. T, Bentley, T. C., and Morelock, T. E. 200. Update on downy mildew of spinach in the United States and Europe. National Spinach Conference. (November 16-17) Fayetteville, AR.
• Villarroel-Zeballos, M. I., Tomlinson, A. N., Correll, J. C., and du Toit, L. J. 2005. Genetic characterization of Verticillium from spinach. National Spinach Conference. (November 16-17) Fayetteville, AR.
• Tomlinson, A. N., Correll, J. C., Feng, C., and Morelock, T. E. 2005. Initiation of BAC library construction and genetic mapping of the spinach genome. National Spinach Conference. (November 16-17) Fayetteville, AR.
• Bentley, T. C., Irish, B. M., Correll, J. C., and Morelock, T. E. 2005. The use of molecular markers for downy mildew resistance and the development of open pollinated spinach differentials for race characterization. National Spinach Conference. (November 16-17) Fayetteville, AR.
• Zhou, E., Jia, Y., Lee, F.N., Lin, M.J., Jia, M.H., Correll, J.C., and Cartwright R. 2005. Evidence of the instability of a telomeric Magnaporthe grisea avirulence gene AVR-Pita in the U.S. Phytopathology 95: S118.

Progress 01/01/04 to 12/30/04

Outputs
Several plant pathogenic fungi including the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum are being examined for their genetic diversity. Also, virulence evolution is being examined in Magnaporthe grisea by evaluating virulence phenotype changes and by monitoring the variation in avirulence genes. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum.

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important in the movement of international agricultural commerce. A great deal is unknown with regard to the inter- and intra-species relationships of these economically important plant pathogens.

Publications

• Correll, J. C., Boza, E. J., Cartwright, R. D. And Ouedraogo, I. 2004. An update on the genetic diversity of the rice blast pathogen in Arkansas. RTWG. New Orleans, LA. 10. Boza, E. J., Correll, J. C., Boza, E. J., Lee, F. N., Gibbons, J. W., Moldenhauer, K. A, and Ouedraogo, I. 2004. Screening the Uniform Regional Rice Nursery for rice blast resistance. RTWG. New Orleans, LA.
• Jia, Y., Wang, Z., Fjellstrom, R.G., Moldenhauer, K. A. K., Azam, M.A., Correll, J., Lee F.N., Xia Y., and Rutger J. N. 2004. Rice Pi-ta gene confers resistance to the major pathotypes of the rice blast fungus in the US. Phytopathology 94:296-30.
• Correll, J. C., Jia, Y., Boza, E. J., and Lee, F. N. 2004, How does the rice blast pathogen defeat a resistance gene? RTWG. New Orleans, LA.
• Ouedraogo, I., Correll, J. C., Boza, E. J., Cartwright, R. D., and Lee, F. N. 2004. Examination of the brown spot and eye spot pathogens of rice and related fungi. RTWG. New Orleans, LA.
• Anderson, R. C., Bentley, T. and Correll, J. C. 2004. Population diversity of the Fusarium oxysporum f. sp. koae , the pathogen of Koa dieback in Hawaii. Phytopathology 94:S4.
• Singh, P., Winston, E. M. Wamishe, Y, Correll, J. C., and Valent, B. 2004. Molecular evolution of rice Pi-ta gene and the fungal Magnaporthe grisea AVR-Pi-ta gene. Phytopathology 94: S47.
• Winston, E. M. , Singh, P., Jia, Y., and Correll, J. C. 2004. Molecular characterization of Magnaporthe grisea avirulence AVR-Pi-ta. Phytopathology 94:S111.
• Giammaria, S. L., Rosso, M. L., Correll, J. C., and Rupe, J. C. 2004. Pathogenicity, mitochondrial DNA, RFLPs, and colony morphology comparisons of isolates of Fusarium virguliforme and F. tucumaniae capable of causing SDS of soybean. Phytopathology 94: S34. 8. Jia, Y., Winston, E. M. , Singh, P., Zhou, E., Wamishe, Y., Jia, M., amd Correll, J. C. 2004. Molecular mechanisms of durable resistance. (November 15-17) Second Annual Rice Functional Genomics Meeting. Tucson, AZ. 9.

Progress 01/01/03 to 12/31/03

Outputs
We are examining the genetic and molecular diversity of several plant pathogenic fungi including the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum.

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important in the movement of international agricultural commerce. A great deal is unknown with regard to the inter- and intra-species relationships of these economically important plant pathogens.

Publications

• Correll, J. C., Jia, Y., Boza, E. J., and Lee, F. N. 2004, How does the rice blast pathogen defeat a resistance gene? RTWG. New Orleans, LA.
• Ouedraogo, I., Correll, J. C., Boza, E. J., Cartwright, R. D., and Lee, F. N. 2004. Examination of the brown spot and eye spot pathogens of rice and related fungi. RTWG. New Orleans, LA.
• Guerber, J. C., Bo, L., Johnston, P. R., and Correll, J. C. 2003. Characterization of diversity of Colletotrichum acutatum sensu lato by sequence analysis of two gene introns, mtDNA and intron RFLPs, and mating compatibility. Mycologia 95:872-895.
• Jia, Y., Wang, Z., Fjellstrom, R.G., Moldenhauer, K. A. K., Azam, M.A., Correll, J., Lee F.N., Xia Y., and Rutger J. N. 2004. Rice Pi-ta gene confers resistance to the major pathotypes of the rice blast fungus in the US. Phytopathology 94: (in press).
• Gonzalez, E., Sutton, T. B., and Correll, J. C., 2003. Characterization of Colletorichum spp. and Glomerella cingulata from apple. Phytopathology 93:S30.
• Viji, G., Uddin, W., and Correll, J. C., 2003. Characterization of Pyricularia grisea from various geographic regions of the United States and Japan using vegetative compatibility and pathogenicity assays. Phytopathology 93:S87.
• Correll, J. C., Guerber, J. C., Bentley, T., and Uddin, W. 2003. Charcterization of Colletotrichum graminicola from turfgrass using mtDNA and intron RFLPs, vegetative compatibility, colony and spore morphology, and intron sequence analysis. Phytopathology 93:S112.
• Correll, J. C., Boza, E. J., Cartwright, R. D. And Ouedraogo, I. 2004. An update on the genetic diversity of the rice blast pathogen in Arkansas. RTWG. New Orleans, LA.
• Boza, E. J., Correll, J. C., Boza, E. J., Lee, F. N., Gibbons, J. W., Moldenhauer, K. A, and Ouedraogo, I. 2004. Screening the Uniform Regional Rice Nursery for rice blast resistance. RTWG. New Orleans, LA.

Progress 01/01/02 to 12/31/02

Outputs
Work continues on various projects including genetic diversity of the rice blast pathogen, Magnaporthe grisea, several species of Colletotrichum, and several forma speciales of Fusarium oxysporum. A range of molecular markers, including mtDNA RFLPs and RFLP and sequence analysis of several introns are being used to characterize the phylogenetic relationships within and between species of Colletotrichum. Also, sexual and vegetative compatibility is being examined in several species of Colletotrichum, Magnaporthe grisea, and Fusarium oxysporum.

Impacts
The efforts of this work should help in more accurately characterizing plant pathogenic fungi which are important concerns in the movement of international agricultural commerce.

Publications

• Guerber, J. C., Liu, B. Correll, J. C., and Johnston P. R. 2003. Characterization of diversity in Colletotrichum acutatum sensu lato by sequence analysis of gene introns, mtDNA and intron RFLPs, and mating compatibility. Mycologia (provisionally accepted).