Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Entire DC Network
Oxalic Acid Leaf Disk Soak Assay Is A New Possibility In Screening For Blight Resistance In Castanea Species, Kaitlyn Harden
Oxalic Acid Leaf Disk Soak Assay Is A New Possibility In Screening For Blight Resistance In Castanea Species, Kaitlyn Harden
Honors Theses
Chestnut blight is a disease caused by the ascomycete fungus Cryphonectria parasitica in the Castanea species. The fungus uses oxalic acid (OA) to attack the tree’s cells. Castanea dentata, the American chestnut, was wiped out by chestnut blight in the early to mid-20th century, but several East Asian Castanea species appear highly resistant to the fungus. To breed resistant American type trees, screening methods are used to enable selection of interspecific hybrids. The alternative small stem assay (aSSA) is a method of screening container-grown hybrid seedlings during their first growing season by directly infecting them with C. parasitica. Some plant …
A Small Stem Assay Using Hypovirulent Cryphonectria Parasitica To Screen Castanea Dentata Backcross F2 Families May Set The Stage For Long-Term Survival, Trish Nguyen
Honors Theses
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 …
Bryophytes Of Goochland County, Virginia, Mikayla Quinn
Bryophytes Of Goochland County, Virginia, Mikayla Quinn
Honors Theses
Bryophytes are non-vascular land plants that include mosses, liverworts, and hornworts. Although easier to overlook because of their smaller size, bryophytes are a fundamental part of the ecosystem. As such, maintaining record of their biodiversity is important. Yet, records of bryophyte species in Goochland County, VA were low compared to more thoroughly documented counties such as Prince Edward County. This study expands the documentation of bryophyte flora and presents a checklist of bryophyte species found Virginia’s Goochland County from 2020-2023. Fieldwork conducted at public and privately-owned properties throughout the county between January 2020 and March 2023 yielded 702 specimens that …
Heading For A Breakdown: Assessing Evolution Through The Hybridization Of Two Sexual Systems, Diamanda A. Zizis
Heading For A Breakdown: Assessing Evolution Through The Hybridization Of Two Sexual Systems, Diamanda A. Zizis
Honors Theses
Hybridization is an important evolutionary pathway that has contributed to the world’s vast biodiversity. In plants, especially angiosperms, hybridization is known to be an important mechanism for speciation, phenotypic divergence, and changes in reproductive systems. Solanum species present an ideal system to investigate how hybridization between two different sexual systems impacts the reproductive and phenotypic biology of the hybrid progeny. Hybrid seeds were acquired from crosses between Australian Solanum species Solanum dioicum (dioecious) and S. ultraspinosum (andromonoecious) in order to track what happens when you cross two plants with different sexual systems. Vegetative and floral morphological measurements were conducted, and …
Changes In Ecosystem Processes And Functional Traits Over An Elevational Gradient, Tiana Issa
Changes In Ecosystem Processes And Functional Traits Over An Elevational Gradient, Tiana Issa
Honors Theses
Elevation gradients have been used to understand how climate change impacts various ecosystems processes by substituting distance across elevation with time, reflecting a previous, colder climate. To monitor the changes in soil organic carbon (SOC), plant community, and functional traits across time in the face of climate change, this study used space-for-time substitution to emulate a long-term study with elevational gradients and revisited the same gradient for nearly two decades to monitor elevational effects across time. With this research, I aim to answer the following questions: (1) How does elevation impact ecosystem processes and alpine plant traits? (2) How does …