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Full-Text Articles in Life Sciences

Habitat And Demography Of The Ozark Chinquapin (Castanea Ozarkensis) At Roaring River State Park In Barry County, Missouri, Danielle Evilsizor Dec 2023

Habitat And Demography Of The Ozark Chinquapin (Castanea Ozarkensis) At Roaring River State Park In Barry County, Missouri, Danielle Evilsizor

Electronic Theses & Dissertations

The Ozark chinquapin, Castanea ozarkensis Ashe, is a chestnut tree with a range concentrated in the Interior Highlands of North America. Like other North American members of Castanea, it was reduced from an overstory tree to an understory shrub by the invasive chestnut blight fungus (Cryphonectria parasitica [Murrill] M.E. Barr) during the early 20th century. However, relatively little is known about the habitat of this species or its health and reproductive capability post chestnut blight. Chapter one of this study analyzed the habitat of this species through a random forest species distribution model (SDM) to predict where …


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 May 2023

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 …


Oxalic Acid Leaf Disk Soak Assay Is A New Possibility In Screening For Blight Resistance In Castanea Species, Kaitlyn Harden May 2023

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 For Chestnut Blight Resistance In Hybrid American Chestnut Trees, Evelyn Odle May 2022

A Small Stem Assay For Chestnut Blight Resistance In Hybrid American Chestnut Trees, Evelyn Odle

Honors Theses

Cryphonectria parasitica (Murr.) Barr is the causal agent for the chestnut blight disease, which was brought to North America in the late 19th century on nursery stock from Japan (Anagnostakis 1987). A pandemic of chestnut blight lasted for the next half century, nearly wiping out all American chestnut trees (Castanea dentata Borkh.). Restoration works to restoring the American chestnut to its native range in North America’s canopy has been going on for the past century. The American Chestnut Foundation has strived to breed a resistant American chestnut by backcross breeding with Chinese species (C. mollissima Blume) since the 1980s. The …


Identification And Characterization Of Hypovirus-Infected Cryphonectria Parasitica Isolates From Biological Control Plots In İzmir, Kütahya, And Sinop, Seçi̇l Akilli Şi̇mşek, Yakup Zekai̇ Katircioğlu, Nora Borst, Deni̇z Çakar, Simone Prospero, Daniel Rigling, Sali̇h Maden Jan 2019

Identification And Characterization Of Hypovirus-Infected Cryphonectria Parasitica Isolates From Biological Control Plots In İzmir, Kütahya, And Sinop, Seçi̇l Akilli Şi̇mşek, Yakup Zekai̇ Katircioğlu, Nora Borst, Deni̇z Çakar, Simone Prospero, Daniel Rigling, Sali̇h Maden

Turkish Journal of Agriculture and Forestry

In a pilot study, a biological control with hypovirus-infected Cryphonectria parasitica was applied in 3 study plots in Turkey, in June 2013. The aim of this study was to evaluate the success of the applied biological control by verifying the establishment of the released hypovirus (CHV-1) strains using molecular markers. C. parasitica isolates were sampled from cankers at 3 different time points: before the biological control treatments (April 2013), and 5 months (October 2013) and 11 months (May 2014) after the treatment. In total, 255 C. parasitica isolates were recovered and characterized. First, the culture morphology and vegetative compatibility type …


Optimization Of Engineered Super Donor Strains Of Cryphonectria Parasitica To Reduce Canker Expansion In A Forest Setting, Amy Michelle Metheny Jan 2019

Optimization Of Engineered Super Donor Strains Of Cryphonectria Parasitica To Reduce Canker Expansion In A Forest Setting, Amy Michelle Metheny

Graduate Theses, Dissertations, and Problem Reports

Chestnut blight, caused by the non-native fungus Cryphonectria parasitica, has decimated American chestnut (Castanea dentata) populations throughout the eastern U.S. over the last century. Biological control of blight, termed hypovirulence, has emerged naturally in the form of a debilitating hypovirus transmitted through hyphal anastomosis among vegetatively compatible C. parasitica strains. Six unlinked vegetative incompatibility (vic) loci regulate hyphal anastomosis and thus, hypovirus transmission, which has limited biocontrol efficacy in genotypically diverse communities. Recently, four of six vic loci have been disrupted to engineer two “super donor” or SD strains. In combining these strains, enhanced transmission …


The Effect Of Insects On Seed Set Of Ozark Chinquapin, Castanea Ozarkensis, Colton Zirkle May 2017

The Effect Of Insects On Seed Set Of Ozark Chinquapin, Castanea Ozarkensis, Colton Zirkle

Graduate Theses and Dissertations

Ozark chinquapin (Castanea ozarkensis), once found throughout the Interior Highlands of the United States, has been decimated across much of its range due to accidental introduction of chestnut blight, Cryphonectria parasitica. Efforts have been made to conserve and restore C. ozarkensis, but success requires thorough knowledge of the reproductive biology of the species. Other Castanea species are reported to have characteristics of both wind and insect pollination, but pollination strategies of Ozark chinquapin are unknown. Experiments were conducted to determine the influence of insects on successful pollination of C. ozarkensis, as measured by production of burs and seeds. Exclosure treatments …


Consequences Of Shifts In Abundance And Distribution Of American Chestnut For Restoration Of A Foundation Forest Tree, Harmony J. Dalgleish, Charles Dana Nelson, John A. Scrivani, Douglass F. Jacobs Dec 2015

Consequences Of Shifts In Abundance And Distribution Of American Chestnut For Restoration Of A Foundation Forest Tree, Harmony J. Dalgleish, Charles Dana Nelson, John A. Scrivani, Douglass F. Jacobs

Forestry and Natural Resources Faculty Publications

Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States Department of Agriculture Forest Service Forest Inventory and Analysis data to quantify the current density and distribution of C. dentata. We then review the literature concerning biogeographic patterns in C. dentata. Currently, 431 ± 30.2 million stems remain. The vast majority (360 ± 22 million) are sprouts < 2.5 cm dbh. Although this number is approximately 10% of the estimated pre-blight population, blight has caused a major shift in the size structure. The current-day population has a larger range, particularly west and north, likely due to human translocation. While climate change could facilitate northward expansion, limited seed reproduction makes this unlikely without assisted migration. Previous research demonstrates that the current, smaller population contains slightly higher genetic diversity than expected, although little information exists on biogeographic patterns in the genetics of adaptive traits. Our research provides a baseline characterization of the contemporary population of C. dentata, to enable monitoring stem densities …


Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold May 2011

Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold

Biological Sciences Faculty Publications

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful …


Biological Control Of Chestnut Canker, Caused By Cryphonectria Parasitica, By Antagonistic Organisms And Hypovirulent Isolates, Seçi̇l Akilli, Yakup Zekai̇ Katircioğlu, Sali̇h Maden Jan 2011

Biological Control Of Chestnut Canker, Caused By Cryphonectria Parasitica, By Antagonistic Organisms And Hypovirulent Isolates, Seçi̇l Akilli, Yakup Zekai̇ Katircioğlu, Sali̇h Maden

Turkish Journal of Agriculture and Forestry

Biological control of chestnut blight was investigated by using 3 hypovirulent isolates of Cryphonectria parasitica, 5 Trichoderma sp., 4 Penicillium sp., and 4 Bacillus sp. isolates. Hypovirulent isolates and antagonistic organisms were obtained from samples collected from the Black Sea region of Turkey, in 2008 and 2009. Effectiveness of the hypovirulent isolates and antagonistic microorganisms was tested on 3-year-old chestnut saplings. In the tests, bark disks of 6 mm were removed from the stem bases and culture disks of the virulent isolate of C. parasitica were first placed into the hole and then the hypovirulent isolate or the antagonistic fungi. …


An Oral History Of The American Chestnut In Southern Appalachia Presentation, Bethany N. Baxter Jul 2009

An Oral History Of The American Chestnut In Southern Appalachia Presentation, Bethany N. Baxter

American Chestnut Oral History Project

Bethany Baxter's defense presentation for the thesis entitled, An oral history of the American chestnut in Southern Appalachia, submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.


American Chestnut Oral History Project Presentation And Interview Clips, Bethany N. Baxter Jan 2009

American Chestnut Oral History Project Presentation And Interview Clips, Bethany N. Baxter

American Chestnut Oral History Project

An interview recorded as part of the original research for the thesis entitled, An oral history of the American chestnut in Southern Appalachia, submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.