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Understanding The Links Between Human Health And Climate Change: Agricultural Productivity And Allergenic Pollen Production Of Timothy Grass(Phleum Pratense L.) Under Future Predicted Levels Of Carbon Dioxide And Ozone, Jennifer M. Albertine

Open Access Dissertations

The prevalence of allergic disease is expected to increase with climate change. Grasses, which have highly allergenic pollen, are widely distributed across the globe. Changes in production and allergen content of grass pollen have not been specifically investigated. We tested the effects of elevated carbon dioxide and ozone on growth, pollen and allergen production of Timothy grass (Phleum pratense L.). Timothy is also used as an agricultural forage crop so changes in plant productivity can also affect humans indirectly. Plants were fumigated in eight chambers at two concentrations of ozone (O₃; 30 and 80 ppb) and carbon dioxide …

Use Of Flame Cultivation As A Nonchemical Weed Control In Cranberry Cultivation, Katherine M. Ghantous

Open Access Dissertations

Cranberry (Vaccinium macrocarpon Ait.) is a woody perennial crop that can remain productive for decades. Competition for resources between cranberries and weeds can depress cranberry farm yields, resulting in large annual crop losses. Renewed interest in reducing chemical inputs into cranberry systems has provided the motivation to evaluate methods, such as flame cultivation (FC), as potential nonchemical options for weed control. Also known as thermal weeding, FC exposes plants to brief periods of high temperature that causes the water in the plant tissue to expand rapidly, rupturing plant cells and leading to necrosis. Various FC methods have been used …

Evaluation Of A Split-Root Nutrition System To Optimize Nutrition Of Basil, Ganisher Djurakulovich Abbasov

Open Access Dissertations

The plant-nutrient-water optimum interaction always has been a problematic program for plant growth and development. This work investigates this interaction using a split root nutrition system to determine possible changes in traditional hydroponics to enhance plant growth and development. While split root nutrition systems have been used experimentally to answer some specific questions, the technique has never been used in a production system for optimizing plant, nutrient, and water interaction. The introduction of hydroponics almost a hundred fifty years ago has not changed this situation fundamentally. Moreover, the norm of fertilizer application on agricultural crops has the advantage of increased …

Interactions Between Floral Mutualists And Antagonists, And Consequences For Plant Reproduction, Nicole Leland Soper Gorden

Open Access Dissertations

While pollinators and leaf herbivores have been a focus of research for decades, floral antagonists have been studied significantly less. Since floral antagonists can be as common as leaf herbivores and have strong impacts on plant reproduction, it is important to understand the role of floral antagonists in the ecology and evolution of flowers. I conducted four experiments to better understand the relationship between plants, floral traits, floral antagonists, and other plant-insect interactions. First, I manipulated resources (light and soil nutrients) that are known to have impacts on plants and floral traits to test how they affect floral antagonists and …

The Evolutionary Genetics Of Seed Shattering And Flowering Time, Two Weed Adaptive Traits In Us Weedy Rice, Carrie S. Thurber

Open Access Dissertations

Weedy rice is a persistent weed of cultivated rice (Oryza sativa) fields worldwide, which competes with the crop and drastically reduces yields. Within the US, two main populations of genetically differentiated weedy rice exist, the straw-hulled (SH) group and the black-hulled awned (BHA) group. Current research suggests that both groups are derived from Asian cultivated rice. However, the weeds differ from the cultivated groups in various morphological traits. My research focus is on the genetic basis of two such traits: seed shattering ability and differences in flowering time. The persistence of weedy rice has been partly attributed to its ability …

Management Of Switchgrass For The Production Of Biofuel, Leryn Elise Gorlitsky

Open Access Dissertations

Switchgrass (Panicum virgatum L.) is a warm-season perennial being considered as a biofuel to meet energy challenges. In Massachusetts, a small state where the price of land is expensive, farmers want to determine if switchgrass can produce sufficient yields for consecutive years to warrant its production. The objective of this study was to determine what harvest management practices affect the vigor and health of switchgrass and which varieties produce the best yields for biofuel production.

Four experiments were conducted from 2009-2012. Twelve varieties were tested to determine their viability in the Massachusetts climate. Five were chosen for further chemical analysis. …

Influence Of Phosphate On The Adsorption/Desorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song

Open Access Dissertations

This work consists of four sections: 1) the adsorption behavior of bovine serum albumin (BSA) by three types of oxide nanoparticles (NPs), TiO2 (50 ± 5 nm), SiO2 (30 ± 5nm), and Al2O3 (150 ± 5 nm for α type and 60 ± 5 nm for γ type) in deionized water; 2) phosphate adsorption on these oxide NPs and bulkparticles (BPs); 3) influence of phosphate ions on BSA adsorption; and 4) BSA desorption from oxide NPs in phosphate solution. BPs were also used for comparison with NPs. For BSA adsorption in deionized water, the adsorption maxima on oxide particles are …

Armillaria In Massachusetts Forests: Ecology, Species Distribution, And Population Structure, With An Emphasis On Mixed Oak Forests, Nicholas Justin Brazee

Open Access Dissertations

The ecology, species distribution, and population structure of Armillaria was investigated in the forests of Massachusetts. From 64 plots at 16 sites, 640 isolates of Armillaria were collected from six forest types (northern hardwoods, mixed oak, pitch pine, white pine, white pine/mixed oak, and eastern hemlock). Armillaria gallica proved to be the most abundant species, making up 316/640 (52%) of all isolations. This was followed by A. solidipes (219/640; 34%), A. mellea (46/640; 7%), A. calvescens (36/640; 6%), A. gemina (16/640; 3%), and A. sinapina (7/640; 1%). Armillaria gallica was routinely encountered causing significant decay of the lower bole on …

Developing An Efficient Cover Cropping System For Maximum Nitrogen Recovery In Massachusetts, Ali Farsad

Open Access Dissertations

Time of planting plays a critical role in nitrogen (N) uptake by rye cover crop (CC). Even a few days of delay in planting can severely decrease CC performance. Evaluating the amount of N accumulation related to time of planting is critical to the farmer who has to optimize the winter rye planting date based on completion of corn harvest, suitable weather conditions and time availability for fall manure application. Winter rye cover crop was planted at 6 planting dates in fall from mid August to early October at weekly intervals from 2004 to 2009.

The results suggest that delay …

Bacterial Toxicity Of Oxide Nanoparticles And Their Effects On Bacterial Surface Biomolecules, Wei Jiang

Open Access Dissertations

Toxicity of nano-scaled Al2O3, SiO2, TiO2 and ZnO to bacteria (Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens) was examined and compared to that of their respective bulk (micro-scaled) counterparts. All nanoparticles (NPs) but TiO2 showed higher toxicity than their bulk counterparts. Toxicity of released metal ions was differentiated from that of the oxide particles. ZnO was the most toxic among the three NPs, causing 100% mortality to the three tested bacteria. TEM images showed attachment of NPs to the bacteria, suggesting that the toxicity was affected by bacterial attachment.

The effects of oxide NPs on bacteria cells and bacterial surface …

Novel Systems For The Functional Characterization Of Genes Related To Paclitaxel Metabolism In Taxus Cell Cultures, Khamkeo Vongpaseuth

Open Access Dissertations

Human society has benefited greatly from plant secondary metabolites, often utilizing a variety of compounds as dyes, food additives, and drugs. In particular, pharmaceutical development has benefited greatly from plant secondary metabolites. One example of this utility is paclitaxel, a highly substituted diterpene approved in the treatment of breast cancer, ovarian cancer, non-small cell lung cancer, and the AIDSrelated Kaposi’s sarcoma. Demand of paclitaxel is likely to increase, due to the current examination of paclitaxel in numerous clinical trials against a variety of other cancers.

Taxus cell culture represents a production source of paclitaxel to meet future demand. However, paclitaxel …

Conservation While Under Invasion: Insights From A Rare Hemiparasitic Plant, Swamp Lousewort (Pedicularis Lanceolata Michx.), Sydne Record

Open Access Dissertations

with non-native invasive species is considered a major threat to many rare native species. As such, invasives removals are a common management strategy. Rare native species that interact uniquely with other organisms in their community (e.g., hemiparasitic plants) may be adversely affected by removing invasives. A management plan for a regionally rare hemiparasitic plant in Massachusetts, Pedicularis lanceolata Michx., identified invasives as a threat, but more quantitative evidence is needed to determine how P. lanceolata‟s persistence is influenced by its co-occurrence with native or invasive hosts. This research asks how P. lanceolata is affected by growth with native versus invasive …

Analyses Of Arabidopsis Yellow Stripe-Like (Ysl) Family Of Metal Transporters, Heng-Hsuan Chu

Open Access Dissertations

Iron is one of the most important micronutrients used by living organisms. Iron is frequently a limiting nutrient for plant growth, and plants are a major source of iron for human nutrition. The most prominent symptom of iron deficiency in plants is interveinal chlorosis, or yellowing between the veins, which appears first in the youngest leaves. Iron deficiency anemia (IDA) is the number one human nutritional deficiency worldwide. In order to solve the problem of iron deficiency, it is desirable to breed plants that have increased iron in those parts that are consumed by humans. To do this, we must …