Research Emphasis:

Nematology Research Program

The primary emphasis of the program is the identification, characterization, and deployment of resistance to nematodes in important crop species. Major pathogens/crop combinations are root-knot nematodes attacking peanut, and root-knot and reniform nematodes attacking cotton. Minor pathogen/crop activities include root-knot nematodes on pecan and forage legumes. Additionally, I am interested in determining the relationship between the polyploid nature of nematode-induced nurse cells (giant cells) and nematode development, especially since recent evidence suggests that as much as two thirds of the nearly 100-fold increase in gene copy number per giant cell is not required for normal development of the parasite.

Peanut

1.Introgression of resistance into a wider array of cultivars, including those with resistance TSWV and Sclerotina blight

2.Conversion of RFLP markers linked to the resistance loci to more efficient PCR-based markers

3.Characterization of a second, recessively inherited gene for resistance, and introgression of this gene into advanced generation peanut breeding lines

Cotton

1.Identify molecular markers linked to loci for resistance root-knot nematodes using RFLP and SSR.

2.Characterize inheritance of resistance in several upland cotton accessions and determine the number of unique genes for resistance that may exist

3.Introgress resistance to reniform nematode from G. barbadense into upland cotton (G. hirsutum) using a backcross breeding program and a pedigree breeding program

Gene copy number in giant cells and nematode development

1.Development of Laser-Microcapture protocols for specific sampling giant cell mRNA, thus allowing quantitative comparison of gene expression at different stages of giant cell development and relative to non-infect host cells.

Teaching

PLPA 610: Host Plant Resistance. A team taught, graduate course that deals with practical aspects of breeding for resistance to arthropods and disease. Topics include breeding strategies for cross-pollinated and self-pollinated crops, sources of resistance, inoculum/inoculation systems for field tests, environmental variability, measurement of disease, and marker-assisted selection. Co-taught with C. W. Smith (plant breeder) and M. K. Harris (entomologist).

PLPA 611: Advance Plant Pathology. Introductory plant pathology class for graduate students with emphasis on the principles and concepts of disease from the level of the plant and pathogen population to molecular events that control pathogenicity and host response to infection. Co-taught with Dan Ebbole. Course notes.

Recent Publications

Bendezu, I. F., E. Morgan, and J. L. Starr. 2004. Hosts of Meloidogyne haplanaria. Nematropica SUMITTED

Church, G.T., J. L. Starr, and C.E. Simpson. 2004. A recessive gene for resistance to Meloidogyne arenaria in interspecific Arachis spp. hybrids. Journal of Nematology SUBMITTED

Dhandaydham, M., L. Charles, H. Zhu, J. L. Starr, T. Huguet, D. R. Cook, J.-M. Prosperi, D. Bird, C. Opperman. 2004. Identification, characterization, and mapping of a root knot nematode resistance gene in Medicago truncatula. Plant Journal SUBMITTED

Besler, B. A., W. J. Grichar, J. L. Starr, S. A. Senseman, and A. J. Jaks. 2004. Effects of row spacing, cultivar, and fungicides for control of foliar and soilborne disease. Peanut Science SUBMITTED

Sikora, R.A ., J. Bridge, and J. L. Starr. 2004 Management Practices: An Overview of Integrated Nematode Management Technologies. Pp xx-xx in Plant parasitic nematodes in subtropical and tropical agriculture, 2nd ed. M. Luc, R. A. Sikora, and J. Bridge, eds. Wallingford, UK: CABI Publications.