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Full-Text Articles in Biology

Heritability Of Latent Period Estimated From Wild-Type And Selected Populations Of Puccinia Triticina, Jeffery S. Lehman, Gregory Shaner Aug 2007

Heritability Of Latent Period Estimated From Wild-Type And Selected Populations Of Puccinia Triticina, Jeffery S. Lehman, Gregory Shaner

Biology and Earth Science Faculty Scholarship

Durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia triticina. To assess the durability of partial resistance, selection experiments were used to explore quantitative variation in parasitic fitness of P. triticina. Fungal populations 881-WT and 882-WT were selected for shortened latent period on partially resistant cvs. CI 13277 and Sw 72469-6 for multiple generations. Fitness components were measured for wild-type and selected fungal populations. Responses to selection and selection differentials were calculated, and broad-sense, realized heritabilities for latent period were estimated for wild-type …


Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffery S. Lehman, Suzu Igarashi, Peter V. Oudemans Jul 2007

Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffery S. Lehman, Suzu Igarashi, Peter V. Oudemans

Biology and Earth Science Faculty Scholarship

Monilinia vaccinii-corymbosi, the causal agent of mummy berry disease, infects blueberry flowers via the gynoecial pathway. To describe the expression of host resistance in highbush blueberry (Vaccinium corymbosum), fungal growth in the styles and colonization of the locules were compared among five blueberry cultivars in a series of controlled greenhouse experiments. Styles were harvested 1 and 4 days postinoculation, and the length colonized by hyphae was determined using fluorescence microscopy. At 8 weeks after inoculation, fruit were harvested and scored for the presence of hyphae in the locules. The infection frequency of styles ranged from 0.33 to 0.71, and only …


Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard Jun 2007

Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard

Winfried S. Peters

Background and Aims Forisomes are Ca2+-dependent contractile protein bodies that form reversible plugs in sieve tubes of faboid legumes. Previous work employed Vicia faba forisomes, a not entirely unproblematic experimental system. The aim of this study was to seek to establish a superior model to study these intriguing actuators.
Methods Existing isolation procedures were modified to study the exceptionally large, tailed forisomes of Canavalia gladiata by differential interference contrast microscopy in vitro. To analyse contraction/expansion kinetics quantitatively, a geometric model was devised which enabled the computation of time-courses of derived parameters such as forisome volume from simple parameters readily determined …


Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch Apr 2007

Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch

Winfried S. Peters

Forisomes are contractile protein bodies that control the effective diameter of the sieve elements of the faboid legumes by reversible, Ca2+-driven changes of shape. Forisomes consist of fibrils; we inferred from available electron-microscopical data (which necessarily provide images of fixed, non-functional forisomes) that a reversible assembly of ordered fibrillar arrays might be involved in the contractile mechanism. Here we examined functional forisomes isolated from Vicia faba L. by differential interference contrast microscopy and polarisation microscopy. We found them birefringent in the longitudinally expanded but not in the contracted state, showing ‘parallel extinction’ with the direction of vibration of the slow …


Ips Pini (Curculionidae: Scolytinae) Is A Vector Of The Fungal Pathogen, Sphaeropsis Sapinea (Coelomycetes), To Austrian Pines, Pinus Nigra (Pinaceae), Justin G.A. Whitehall, Jeffery S. Lehman, Pierluigi Bonello Feb 2007

Ips Pini (Curculionidae: Scolytinae) Is A Vector Of The Fungal Pathogen, Sphaeropsis Sapinea (Coelomycetes), To Austrian Pines, Pinus Nigra (Pinaceae), Justin G.A. Whitehall, Jeffery S. Lehman, Pierluigi Bonello

Biology and Earth Science Faculty Scholarship

Sphaeropsis sapinea (Fr.:Fr.) Dyko and Sutton, is among the most common and widely distributed pathogens of conifers worldwide. S. sapinea is disseminated over short distances by rain splash and moist wind, but significant knowledge gaps regarding long-range dispersal remain. Our objective was to determine whether or not the pine engraver beetle, Ips pini Say, is a vector of the pathogen onto Austrian pines (Pinus nigra Arnold). In 2004 and 2005, individuals of I. pini were collected with pheromone traps at two locations in central Ohio (197 and 1,017 individuals for 2004 and 2005, respectively) and screened for the presence of …


Conservation Of B Class Gene Expression In The Second Whorl Of A Basal Grass And Outgroups Links The Origin Of Lodicules And Petals, Clinton Whipple, Michael Zanis, Elizabeth Kellogg, Robert Schmidt Jan 2007

Conservation Of B Class Gene Expression In The Second Whorl Of A Basal Grass And Outgroups Links The Origin Of Lodicules And Petals, Clinton Whipple, Michael Zanis, Elizabeth Kellogg, Robert Schmidt

Biology Department Faculty Works

Studies of flower development in core eudicot species have established a central role for B class MADS-box genes in specifying petal and stamen identities. Similarly in maize and rice, B class genes are essential for lodicule and stamen specification, suggesting homology of petals and lodicules and conservation of B class gene activity across angiosperms. However, lodicules are grass-specific organs with a morphology distinct from petals, thus their true homology to eudicot and nongrass monocot floral organs has been a topic of debate. To understand the relationship of lodicules to the sterile floral organs of nongrass monocots we have isolated and …


Additions To The Flora Of Connecticut, Gordon C. Tucker Jan 2007

Additions To The Flora Of Connecticut, Gordon C. Tucker

Faculty Research & Creative Activity

Since the publication of the Connecticut checklist by Dowhan (1979), new state records have continued to appear. These were summarized by Mehrhoff (1995), including some made by Tucker ( 1987, 1991 ). Although geographically distant, the flora of Connecticut has continued to hold my attention since the publication of a flora of the southeastern part of the state (Tucker 1995). Over the past decade, I have made several collections that are new records for the state flora. These new records are reported in this paper, as well as a 1970 collection of Coronilla scorpio ides that was never added to …


Performance Of Dionaea Muscipula As Influenced By Developing Vegetation, James O. Luken Jan 2007

Performance Of Dionaea Muscipula As Influenced By Developing Vegetation, James O. Luken

Biology

Demography, growth, and flowering of Dionaea muscipula (Venus' fly trap) were studied during three years (2003–2005) following prescribed fire. Data were collected in permanent quadrats where the developing vegetation was either repeatedly clipped or allowed to grow. Clipping increased light availability at the soil surface. Over the study period, seedling establishment and flowering declined with increasing time since the last prescribed burn. Seedling densities did not differ between clipped and control quadrats, although greater numbers of seedlings grew to adult size in control quadrats and this significantly influenced population size-class structure. Clipping had no effect on leaf number or senescence, …