A heavy metal biossay based on percent spore germination of the sensitive fern,Onoclea sensibilis

1980 ◽  
Vol 24 (1) ◽  
pp. 489-495 ◽  
Author(s):  
Raymond L. Petersen ◽  
Damon Arnold ◽  
David G. Lynch ◽  
Steven A. Price
Keyword(s):  
Heavy Metal ◽  
Spore Germination ◽  
Onoclea Sensibilis

scholarly journals Spore Germination and Rhizoid Differentiation in Onoclea sensibilis

1984 ◽  
Vol 74 (3) ◽  
pp. 656-662 ◽  
Author(s):  
Clark S. Huckaby ◽  
John H. Miller
Keyword(s):  
Spore Germination ◽  
Onoclea Sensibilis

scholarly journals Heavy-Metal Stress and Developmental Patterns of Arbuscular Mycorrhizal Fungi

2004 ◽  
Vol 70 (11) ◽  
pp. 6643-6649 ◽  
Author(s):  
Teresa E. Pawlowska ◽  
Iris Charvat
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Spore Germination ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Metal Stress ◽  
Soil Conditions ◽  
Global Changes ◽  
Extraradical Mycelium ◽  
Metal Concentrations

ABSTRACT The rate of global deposition of Cd, Pb, and Zn has decreased over the past few decades, but heavy metals already in the soil may be mobilized by local and global changes in soil conditions and exert toxic effects on soil microorganisms. We examined in vitro effects of Cd, Pb, and Zn on critical life stages in metal-sensitive ecotypes of arbuscular mycorrhizal (AM) fungi, including spore germination, presymbiotic hyphal extension, presymbiotic sporulation, symbiotic extraradical mycelium expansion, and symbiotic sporulation. Despite long-term culturing under the same low-metal conditions, two species, Glomus etunicatum and Glomus intraradices, had different levels of sensitivity to metal stress. G. etunicatum was more sensitive to all three metals than was G. intraradices. A unique response of increased presymbiotic hyphal extension occurred in G. intraradices exposed to Cd and Pb. Presymbiotic hyphae of G. intraradices formed presymbiotic spores, whose initiation was more affected by heavy metals than was presymbiotic hyphal extension. In G. intraradices grown in compartmentalized habitats with only a portion of the extraradical mycelium exposed to metal stress, inhibitory effects of elevated metal concentrations on symbiotic mycelial expansion and symbiotic sporulation were limited to the metal-enriched compartment. Symbiotic sporulation was more sensitive to metal exposure than symbiotic mycelium expansion. Patterns exhibited by G. intraradices spore germination, presymbiotic hyphal extension, symbiotic extraradical mycelium expansion, and sporulation under elevated metal concentrations suggest that AM fungi may be able to survive in heavy metal-contaminated environments by using a metal avoidance strategy.

Complementary Z-Contrast Imaging and Digital Image Processing

1985 ◽  
Vol 43 ◽  
pp. 304-305
Author(s):  
K. N. Colonna ◽  
G. Oliphant
Keyword(s):  
Image Processing ◽  
Heavy Metal ◽  
Digital Image Processing ◽  
Digital Image ◽  
Biological Tissue ◽  
Biological Imaging ◽  
Tissue Preparation ◽  
Contrast Imaging ◽  
Imaging Tool ◽  
Z Contrast

Harmonious use of Z-contrast imaging and digital image processing as an analytical imaging tool was developed and demonstrated in studying the elemental constitution of human and maturing rabbit spermatozoa. Due to its analog origin (Fig. 1), the Z-contrast image offers information unique to the science of biological imaging. Despite the information and distinct advantages it offers, the potential of Z-contrast imaging is extremely limited without the application of techniques of digital image processing. For the first time in biological imaging, this study demonstrates the tremendous potential involved in the complementary use of Z-contrast imaging and digital image processing.Imaging in the Z-contrast mode is powerful for three distinct reasons, the first of which involves tissue preparation. It affords biologists the opportunity to visualize biological tissue without the use of heavy metal fixatives and stains. For years biologists have used heavy metal components to compensate for the limited electron scattering properties of biological tissue.

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