Theses and Dissertations


Issuing Body

Mississippi State University


Ahn, Seung Joon

Committee Member

Wubben, Martin J.

Committee Member

Li, Ling

Committee Member

Sabanadzovic, Sead

Other Advisors or Committee Members

Popescu, Sorina

Date of Degree


Document Type

Dissertation - Open Access



Degree Name

Doctor of Education (Ed.S.)


College of Agriculture and Life Sciences


Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology


Upland cotton (Gossypium hirsutum ) is an important fiber crop grown throughout the southern United States. Plant-pathogenic nematodes are worm-like animals that feed on the roots of most agronomic crops, including cotton. The southern root-knot nematode (Meloidogyne incognita, RKN) and the reniform nematode (Rotylenchulus reniformis, RN) cause significant yield losses in cotton every year. Current sources of resistance are effective but limited, therefore historical screenings of cotton accessions were revisited in search for novel resistance sources. None were identified but many of the screened accessions possessed markers of known root-knot nematode and reniform nematode resistance. The emerging guava root-knot nematode (Meloidogyne enterolobii, GRKN) is a risk for upland cotton production, and identifying host plant resistance would greatly reduce the yield losses for growers. Assays were conducted on the currently available RN and RKN resistance sources inoculated with GRKN. No known nematode resistance gene suppressed GRKN infection, indicating that work must be done to protect crops from the eventual discovery of GRKN in Mississippi fields. Using the same resistance sources, tests were conducted to determine if the currently available resistances to RKN and RN offer any suppression of secondary infection of non-target nematode species for resistance. This is referred to as systemic acquired resistance, which is the induction of non-specific plant defense. Assays found that early inoculation with the nematode targeted by resistance did not effect infection by a secondary nematode species.