Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

The Role Of Fusarium Mycotoxins In Seedling Infection Of Soybeans, Wheat And Maize, Tracy L. Bruns Jan 2015

The Role Of Fusarium Mycotoxins In Seedling Infection Of Soybeans, Wheat And Maize, Tracy L. Bruns

Graduate Theses and Dissertations

Fusarium graminearum and Fusarium verticillioides are fungal plant pathogens that can cause yield losses, reductions in grain quality, and produce mycotoxins that can cause serious diseases in animals and humans when contaminated grain is consumed. Both pathogens can infect and cause disease in seedlings. F. graminearum infects cereals and other crops and produces mycotoxins including deoxynivalenol (DON), which can act as a virulence factor for Gibberella ear rot in maize and head blight of wheat. F. verticillioides infects maize and produces fumonisins, a group of mycotoxins with phytotoxic properties. Previous research into the role of these mycotoxins in seedling diseases ...


Raffaelea Spp. From Five Ambrosia Beetles In The Genera Xyleborinus And Cyclorhipidion (Coleoptera: Curcurlionidae: Scolytinae: Xyleborini), Yeganeh Gharabigloozare Jan 2015

Raffaelea Spp. From Five Ambrosia Beetles In The Genera Xyleborinus And Cyclorhipidion (Coleoptera: Curcurlionidae: Scolytinae: Xyleborini), Yeganeh Gharabigloozare

Graduate Theses and Dissertations

Five undescribed species of Raffaelea (Ophiostomatales), as well as Raffaelea sulphurea, were isolated and illustrated from the ambrosia beetle tribe Xyleborini: Raffaelea sulphurea and Raffaelea sp. A from Xyleborinus saxeseni; Raffaelea sp. B and Raffaelea sp. C from Xyleborinus attenuatus; Raffaelea sp. D from Xyleborinus gracilis; Raffaelea sp. F from Cyclorhipidion bodoanum; and Raffaelea sp. G from C. pelliculosum.

Each fungal symbiont was isolated from a single beetle host species or its galleries and characterized by culture morphology and DNA sequencing. Analysis of of 18S rDNA and translocation elongation factor sequences of five undescribed symbionts (Raffaelea sulphurea, Raffaelea sp. B ...


Detection And Management Of Colletotrichum Acutatum Sensu Lato On Strawberry, Xiaoyu Zhang Jan 2015

Detection And Management Of Colletotrichum Acutatum Sensu Lato On Strawberry, Xiaoyu Zhang

Graduate Theses and Dissertations

Colletotrichum acutatum sensu lato, one of the most economically damaging pathogens of strawberry, is the primary causal agent of anthracnose fruit rot (AFR). A key challenge in managing AFR is detecting the pathogen on asymptomatic plants. To meet this need, a loop-mediated isothermal amplification (LAMP) assay was developed that incorporated two sets of primers: LITSG1 targeted on the ITS region of ribosomal DNA and Ltub2 on the β-tubulin 2 gene. In pure culture assays, Ltub2 was specific for detection of C. acutatum, whereas LITSG1 detected C. acutatum and two additional anthracnose pathogens, C. gloeosporioides and C. fragariae. LITSG1 had 10-fold ...


Seedborne Black Aspergillus Species As Maize Seedling Pathogens: Role Of Fumonisin Production And Interaction With Soilborne Pythium Species, Laura Kaelia Weieneth Jan 2015

Seedborne Black Aspergillus Species As Maize Seedling Pathogens: Role Of Fumonisin Production And Interaction With Soilborne Pythium Species, Laura Kaelia Weieneth

Graduate Theses and Dissertations

Twenty-six strains of black Aspergillus (Aspergillus section Nigri) were studied as seedling pathogens of maize. There were two major research components. The first component was an evaluation of the pathogenicity of isolates from several black Aspergillus species and a comparison of the pathogenicity of isolates with and without fumonisin production. This was accomplished by testing inoculated seeds in warm germination and cold tests, and by evaluating growth of inoculated seeds in rolled paper towel assays. In the second component, four of these species were selected for evaluation of interactions between Aspergillus and Pythium as a seedling disease complex in maize ...


Ecological Specialization Of Tubakia Iowensis, And Searching For Variation In Resistance To Bur Oak Blight, Ashley Marie West Jan 2015

Ecological Specialization Of Tubakia Iowensis, And Searching For Variation In Resistance To Bur Oak Blight, Ashley Marie West

Graduate Theses and Dissertations

Tubakia iowensis was recently recognized and described as the causative agent of bur oak blight. The pathogen causes vein necrosis and early season leaf death on Quercus macrocarpa (bur oak). Tubakia sp. B, an undescribed species, was isolated from bur oak and other oaks and was found to be morphologically indistinguishable from T. iowensis. In chapter 2, T. iowensis and Tubakia sp. B differed in causing a greater amount of necrosis on inoculated leaf blade tissue and in causing less petiole death and fewer conidiomata (pustules) after inoculation of expanding shoots. Both Tubakia spp. caused vein necrosis, but Tubakia sp ...


Bacterial Wilt Of Cucurbits: Impact Of Plant Age On Symptom Progression And Pathogen Movement And Locating Genes Associated With Host Preference And Pathogenesis In E. Tracheiphila, Qian Liu Jan 2015

Bacterial Wilt Of Cucurbits: Impact Of Plant Age On Symptom Progression And Pathogen Movement And Locating Genes Associated With Host Preference And Pathogenesis In E. Tracheiphila, Qian Liu

Graduate Theses and Dissertations

Bacterial wilt of cucurbits is a devastating disease of cucurbit crops in the mid-Atlantic region of the USA. Caused by Erwinia tracheiphila, it is transmitted by striped (Acalymma vittatum (F.)) and spotted (Diabrotica undecimpunctata howardi (Barber)) cucumber beetles. The management of bacterial wilt relies primarily on the control of cucumber beetles with insecticides. However, alternative management strategies are needed due to the high cost of insecticides and their negative impact on the environment. Understanding bacterial wilt etiology and the ecology of E. tracheiphila may provide insights to help control bacterial wilt of cucurbits.

The first objective of my thesis research ...


Emerging Issues In The U.S. Corn Belt: Infection Of Corn By Clavibacter Michiganensis Subsp. Nebraskensis And Use Of Foliar Fungicides To Protect Yield, Salome Mallowa Obura Jan 2015

Emerging Issues In The U.S. Corn Belt: Infection Of Corn By Clavibacter Michiganensis Subsp. Nebraskensis And Use Of Foliar Fungicides To Protect Yield, Salome Mallowa Obura

Graduate Theses and Dissertations

Currently two major issues pertaining to disease management in corn production in the US Corn Belt are the spread of Goss's wilt and leaf blight caused by Clavibacter michiganensis subsp. nebraskensis (Cmn), and the use of foliar fungicides on corn for `plant health' benefits. This dissertation presents data regarding infection of corn by Cmn, and fungicide effects on disease management and yield.

Greenhouse and laboratory research was undertaken to determine if infection of corn by Cmn may occur without severe wounding, such as that caused by hail, sand blasting or wind damage. Corn plants with no obvious wounding were ...