PLPT 496/892: Disease Dynamics & Evolution—A Peer Review of Teaching Project Benchmark Portfolio

This benchmark course portfolio was developed as a component of the University of Nebraska Peer Review of Teaching. The course selected for this portfolio was a new course developed and taught as an Independent Study PLPT 496/892. The working title for the course was Disease Dynamics and Evolution. This course was designed to cover core concepts of disease ecology and pathogen emergence/evolution. Concepts were organism-agnostic and important for understanding infectious diseases of humans, animals, and plants. The course format was lecture-based and inquiry driven, using primary literature as case studies. The goal of this course was to use interesting and intriguing case studies of infectious diseases to develop critical thinking as scientists. The course was designed to be appropriate for a wide variety of biology students, with interests in ecology, environmental biology, animal, plant, and human biology to microbiology, pre-vet and pre-med. A pre-requisite for undergraduates was BIOS 312 or permission of instructor. It is expected the course will be offered in the spring semester of even-numbered years

Upper Canopy Collection and Identification of Grapevines (\u3ci\u3eVitis\u3c/i\u3e) from Selected Forests in the Southeastern United States

Woody grapevines (Vitis spp.) are common in the deciduous forests of the southeastern United States. Their growth habit makes leaf collection challenging and polymorphic leaves make identification of species difficult. Mature grapevines can grow up to 48 cm in diameter at breast height and reach the upper canopy of trees more than 35 m in height. Leaf morphology is the most readily available character used for species identification. However, most mature grapevines do not produce leaves below the upper canopy and if they do, these leaves are morphologically indistinguishable from other species. In order to sample leaves from mature grapevines, the doubled rope climbing method was used to access the canopy in Great Smoky Mountains National Park in Tennessee, Daniel Boone National Forest and Berea College Forest in Kentucky, and Ha Ha Tonka State Park in Missouri. Leaf voucher specimens were collected from the upper canopy and used to create a modified key to species for those regions. The purposes of this paper are to report a new method for collecting grapevine leaf vouchers from the upper canopy of trees, to present a modified key used for identifying dried leaf vouchers of Vitis species, and to present a discussion of the possible utility of this research for future studies

Upper Canopy Collection and Identification of Grapevines (\u3ci\u3eVitis\u3c/i\u3e) from Selected Forests in the Southeastern United States

Woody grapevines (Vitis spp.) are common in the deciduous forests of the southeastern United States. Their growth habit makes leaf collection challenging and polymorphic leaves make identification of species difficult. Mature grapevines can grow up to 48 cm in diameter at breast height and reach the upper canopy of trees more than 35 m in height. Leaf morphology is the most readily available character used for species identification. However, most mature grapevines do not produce leaves below the upper canopy and if they do, these leaves are morphologically indistinguishable from other species. In order to sample leaves from mature grapevines, the doubled rope climbing method was used to access the canopy in Great Smoky Mountains National Park in Tennessee, Daniel Boone National Forest and Berea College Forest in Kentucky, and Ha Ha Tonka State Park in Missouri. Leaf voucher specimens were collected from the upper canopy and used to create a modified key to species for those regions. The purposes of this paper are to report a new method for collecting grapevine leaf vouchers from the upper canopy of trees, to present a modified key used for identifying dried leaf vouchers of Vitis species, and to present a discussion of the possible utility of this research for future studies

PLPT 496/892: Disease Dynamics & Evolution—A Peer Review of Teaching Project Benchmark Portfolio

This benchmark course portfolio was developed as a component of the University of Nebraska Peer Review of Teaching. The course selected for this portfolio was a new course developed and taught as an Independent Study PLPT 496/892. The working title for the course was Disease Dynamics and Evolution. This course was designed to cover core concepts of disease ecology and pathogen emergence/evolution. Concepts were organism-agnostic and important for understanding infectious diseases of humans, animals, and plants. The course format was lecture-based and inquiry driven, using primary literature as case studies. The goal of this course was to use interesting and intriguing case studies of infectious diseases to develop critical thinking as scientists. The course was designed to be appropriate for a wide variety of biology students, with interests in ecology, environmental biology, animal, plant, and human biology to microbiology, pre-vet and pre-med. A pre-requisite for undergraduates was BIOS 312 or permission of instructor. It is expected the course will be offered in the spring semester of even-numbered years

PLPT 496/892: Disease Dynamics & Evolution—A Peer Review of Teaching Project Benchmark Portfolio

This benchmark course portfolio was developed as a component of the University of Nebraska Peer Review of Teaching. The course selected for this portfolio was a new course developed and taught as an Independent Study PLPT 496/892. The working title for the course was Disease Dynamics and Evolution. This course was designed to cover core concepts of disease ecology and pathogen emergence/evolution. Concepts were organism-agnostic and important for understanding infectious diseases of humans, animals, and plants. The course format was lecture-based and inquiry driven, using primary literature as case studies. The goal of this course was to use interesting and intriguing case studies of infectious diseases to develop critical thinking as scientists. The course was designed to be appropriate for a wide variety of biology students, with interests in ecology, environmental biology, animal, plant, and human biology to microbiology, pre-vet and pre-med. A pre-requisite for undergraduates was BIOS 312 or permission of instructor. It is expected the course will be offered in the spring semester of even-numbered years

Fine-Scale Genetic Structure of \u3ci\u3eMonilinia fructicola\u3c/i\u3e During Brown Rot Epidemics Within Individual Peach Tree Canopies

The purpose of this study was to determine the fine-scale genetic structure of populations of the brown rot pathogen Monilinia fructicola within individual peach tree canopies to better understand within-tree plant pathogen diversity and to complement previous work on spatiotemporal development of brown rot disease at the canopy level. Across 3 years in a total of six trees, we monitored disease development, collected isolates from every M. fructicola symptom during the course of the season, and created high-resolution three-dimensional maps of all symptom and isolate locations within individual canopies using an electromagnetic digitizer. Each canopy population (65 to 173 isolates per tree) was characterized using a set of 13 microsatellite markers and analyzed for evidence of spatial genetic autocorrelation among isolates during the epidemic phase of the disease. Results showed high genetic diversity (average uh = 0.529) and high genotypic diversity (average D = 0.928) within canopies. The percentage of unique multilocus genotypes within trees was greater for blossom blight isolates (78.2%) than for fruit rot isolates (51.3%), indicating a greater contribution of clonal reproduction during the preharvest epidemic. For fruit rot isolates, between 54.2 and 81.7% of isolates were contained in one to four dominant clonal genotypes per tree having at least 10 members. All six fruit rot populations showed positive and significant spatial genetic autocorrelation for distance classes between 0.37 and 1.48 m. Despite high levels of within-tree pathogen diversity, the contribution of locally available inoculum combined with short-distance dispersal is likely the main factor generating clonal population foci and associated spatial genetic clustering within trees

Importance of Myxomycetes in Biological Research and Teaching

Myxomycetes, the true slime molds, are highlighted in research and teaching that emphasizes various stages of the life cycle as experimental models. Past and current phylogenetic classifications of Myxomycetes on the tree of life are presented. Life cycle stages are illustrated, described, and discussed. Simple laboratory demonstrations and experiments are described that include spore germination, spore release, and moist chamber cultures utilizing organic matter from various microhabitats. Novel compounds isolated from fruiting bodies and plasmodia of 22 myxomycete species are tabulated, some of which exhibit biological activity that function as antibiotics, antimicrobials, and are cytotoxic to cancer cells. Aeroallergens include myxomycete spores, especially Fuligo septica. The plasmodial stage of Physarum polycephalum has been used as a model research system to study responses to gravity in outer space, solve the shortest pathway through a maze exhibiting “primitive intelligence,” develop a biologically controlled robot, discover what controls synchronous nuclear division, and the development of a new drug Polycefin that shows promise in the treatment of breast and brain cancerous tumors. Life span and senescence experiments showed that aging and longevity were under nuclear control. Environmental ground pollution may be remediated by myxomycete fruiting bodies and plasmodia of Fuligo septica that hyper-accumulate and concentrate highly toxic levels of zinc several thousand fold greater than site vegetation and lesser significant amounts of barium, cadmium, iron, manganese, and strontium. Tree canopy research has shown that aerial pollution results in the decrease of myxomycete species richness at higher elevations for Abies fraseri in Great Smoky Mountains National Park. At lower elevations and locations in the United States of America living Juniperus virginiana tree canopies have the highest species richness (54). Myxomycetes that occur mostly on the bark surface of living trees, shrubs, woody vines, prairie and desert plants fall into five pH groups: low pH (3.5– 4.5), mid-range pH (4.6–6.0) and pH (6.1–7.5), high pH values (7.6–10.0), and a broad spectrum of pH (3.5–7.5). When more environmental parameters are better known myxomycetes may one day serve as the basis for evaluating the impact of pollutants on living trees

Importance of Myxomycetes in Biological Research and Teaching

Myxomycetes, the true slime molds, are highlighted in research and teaching that emphasizes various stages of the life cycle as experimental models. Past and current phylogenetic classifications of Myxomycetes on the tree of life are presented. Life cycle stages are illustrated, described, and discussed. Simple laboratory demonstrations and experiments are described that include spore germination, spore release, and moist chamber cultures utilizing organic matter from various microhabitats. Novel compounds isolated from fruiting bodies and plasmodia of 22 myxomycete species are tabulated, some of which exhibit biological activity that function as antibiotics, antimicrobials, and are cytotoxic to cancer cells. Aeroallergens include myxomycete spores, especially Fuligo septica. The plasmodial stage of Physarum polycephalum has been used as a model research system to study responses to gravity in outer space, solve the shortest pathway through a maze exhibiting “primitive intelligence,” develop a biologically controlled robot, discover what controls synchronous nuclear division, and the development of a new drug Polycefin that shows promise in the treatment of breast and brain cancerous tumors. Life span and senescence experiments showed that aging and longevity were under nuclear control. Environmental ground pollution may be remediated by myxomycete fruiting bodies and plasmodia of Fuligo septica that hyper-accumulate and concentrate highly toxic levels of zinc several thousand fold greater than site vegetation and lesser significant amounts of barium, cadmium, iron, manganese, and strontium. Tree canopy research has shown that aerial pollution results in the decrease of myxomycete species richness at higher elevations for Abies fraseri in Great Smoky Mountains National Park. At lower elevations and locations in the United States of America living Juniperus virginiana tree canopies have the highest species richness (54). Myxomycetes that occur mostly on the bark surface of living trees, shrubs, woody vines, prairie and desert plants fall into five pH groups: low pH (3.5– 4.5), mid-range pH (4.6–6.0) and pH (6.1–7.5), high pH values (7.6–10.0), and a broad spectrum of pH (3.5–7.5). When more environmental parameters are better known myxomycetes may one day serve as the basis for evaluating the impact of pollutants on living trees

Impact of maize hormonal interactions on the performance of \u3ci\u3eSpodoptera frugiperda\u3c/i\u3e in plants infected with \u3ci\u3eClavibacter michiganensis\u3c/i\u3e subsp. \u3ci\u3enebraskensis\u3c/i\u3e

In nature, plants interact with multiple organisms, below and aboveground. Although interactions of plants with single biotic stressors are well characterized, knowledge of how the immune system responds to multiple biotic stressors is lacking. It is known that the two most important pathways involved in the plant immune defenses are jasmonic acid (JA) and salicylic acid (SA). The crosstalk between these plant hormonal signaling pathways seems to fine-tune the plant responses to different stressors. In this study, we characterized maize (Zea mays) hormonal interactions under the attack of two economically important pests: the bacterial pathogen that causes Goss’s bacterial wilt and leaf blight (Clavibacter michiganensis subsp. nebraskensis), and the chewing insect, fall armyworm (Spodoptera frugiperda). Our results indicate that the Goss’s wilt-resistant maize plants when pretreated with bacteria became more vulnerable to the subsequent attack by the fall armyworm larvae. Furthermore, plant hormone analysis demonstrated that the antagonistic interactions of JA-Isoleucine (JA-Ile), biologically active form of JA, and SA in maize plants contributed to enhanced plant susceptibility to herbivory. Collectively, our results suggest that plant hormonal interactions may play a major role in maize defense against multiple biotic stressors. Furthermore, this study will improve our understanding and ability to predict plant-induced hormone responses in an economically important crop

Phytophthora ramorum

Phytophthora ramorum is a recently emerged plant pathogen and causal agent of one of the most destructive and devastating diseases currently affecting US horticulture and forests (Rizzo et al. 2002, 2005). This oomycete pathogen was discovered in Marin County, California, in the mid-1990s, causing sudden oak death on coast live oak (Quercus agrifolia) and tanoak (Notholithocarpus densiflorus) and simultaneously discovered in Europe causing foliar blight on Rhododendron and Viburnum (Rizzo et al. 2002; Werres et al. 2001). It is now known to affect more than 100 plant species, including economically important nursery and forest host species (Frankel 2008; Rizzo et al. 2005; Tooley et al. 2004; Tooley and Kyde 2007)