Project Director

Craddock, J. Hill

Department Examiner

Caskey, Jodi; Hayes, Loren D.

Department

Dept. of Biological and Environmental Sciences

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

By combining the results of blight resistance breeding and the application of hypovirulence as a biocontrol, populations of resistant hybrid trees could be deployed together with a less pathogenic strain of Cryphonectria parasitica (Murr.) Barr. I used a small stem assay to screen seedlings in thirteen half-sibling backcross F2 families with an attenuated strain of C. parasitica containing the Cryphonectria parasitica hypovirus-1 (CHV-1) Euro7 virus. The experiment was set up as a randomized complete block design in 2-gallon containers. Measurements of canker length and morphology were gathered at 90 days post-inoculation. Although statistically significant differences were seen between canker lengths in C. dentata and C. mollissima control groups, no statistically significant differences were seen between any of the hybrid families as shown by Duncan’s multiple range test. Phenotypes elucidated using the SSA should not be used to make artificial selections within families, but the SSA can verify that parental selections were accurate. All surviving trees will be planted in an experimental orchard in middle Tennessee to create a potentially long-lasting population of disease resistant trees.

Acknowledgments

Thank you to Dr. Hill Craddock for four years of guidance. Thank you to Dr. Jodi Caskey and Dr. Loren Hayes for agreeing to be on my committee on the spot. Thank you to the Fortwood Greenhouse crew, especially Dr. Paola Zannini and all volunteers from TACF, for helping me plant, organize, and water my trees. Thank you to Amy Metheny from West Virginia University for sending me the fungal isolates. Thank you to Dr. Jared Westbrook for showing me the R code to make the figures in the manuscript. Thank you to the Tucker Foundation for supporting me through scholarships for three years. Thank you to my college roommate Hope Smith for emotional support throughout this project.

Degree

B. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Science.

Date

5-2023

Subject

American chestnut--Breeding; American chestnut--Biocontrol; Chestnut blight

Keyword

american chestnut; chestnut blight; early screening; hypovirulence; backcross; resistance

Discipline

Plant Pathology

Document Type

Theses

Extent

iii, 37 leaves

DCMI Type

Text

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

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