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Articles 1 - 5 of 5

Full-Text Articles in Plant Sciences

Lignin Degradation In Wood-Feeding Insects, Scott M. Geib, Timothy R. Filley, Patrick G. Hatcher, Kelli Hoover, John E. Carlson, Maria Del Mar Jimenez-Gasco, Akiko Nakagawa-Izumi, Rachel L. Sleighter, Ming Tien Jan 2008

Lignin Degradation In Wood-Feeding Insects, Scott M. Geib, Timothy R. Filley, Patrick G. Hatcher, Kelli Hoover, John E. Carlson, Maria Del Mar Jimenez-Gasco, Akiko Nakagawa-Izumi, Rachel L. Sleighter, Ming Tien

Chemistry & Biochemistry Faculty Publications

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut …


Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid Jan 2008

Microspore Wall Morphogenesis And Orbicule Ultrastructure Of Isoetes, Khalid Alarid

Biological Sciences Theses & Dissertations

The microspore wall morphogenesis and orbicule ultrastructure of Isoetes were studied using electron microscopy. Microspore wall morphogenesis in five species of Isoetes (I. appalachiana, I. engelmannii, I. hyemalis, I. piedmontana, and an undescribed species from York Co., VA, USA) was studied using scanning and transmission electron microscopy. Results show that they generally have the same developmental stages in terms of microspore wall morphogenesis. The mature microspore wall consisted of four layers: perispore, paraexospore, exospore and endospore. Paraexospore formation began during the tetrad stage. The exospore was then formed between the paraexospore and the plasma membrane. During the free spore …


Systematic Revision Of Elaphoglossum (Dryopteridaceae) In French Polynesia, With The Description Of Three New Species, Germinal Rouhan, David H. Lorence, Timothy J. Motley, Judith Garrison Hanks, Robbin C. Moran Jan 2008

Systematic Revision Of Elaphoglossum (Dryopteridaceae) In French Polynesia, With The Description Of Three New Species, Germinal Rouhan, David H. Lorence, Timothy J. Motley, Judith Garrison Hanks, Robbin C. Moran

Biological Sciences Faculty Publications

Species descriptions and a key for the nine species of Elaphoglossum (Dryopteridaceae) in French Polynesia are provided. Three new species are described: E. austromarquesense from the southern Marquesas Islands, E. florencei from Raiatea and Moorea, and E. meyeri from Rapa. Each species is illustrated by a line drawing of the habit, and spore images using a scanning electron microscope. Images of scales, one of the most important diagnostic characters in the genus, are also included. © 2008 The Linnean Society of London.


Anther Appendages Of Incarvillea Trigger A Pollen-Dispensing Mechanism, Yi Han, Can Dai, Chun-Feng Yang, Qing-Feng Wang, Timothy J. Motley Jan 2008

Anther Appendages Of Incarvillea Trigger A Pollen-Dispensing Mechanism, Yi Han, Can Dai, Chun-Feng Yang, Qing-Feng Wang, Timothy J. Motley

Biological Sciences Faculty Publications

Background and Aims Anther appendages play diverse roles in anther dehiscence and pollen dispersal. This study aims to explore the pollen-dispensing mechanism triggered by special anther appendages in Incarvillea arguta.

Methods Field studies were conducted to record floral characteristics, pollinator visitations, and flower-pollinator interactions. Measurements of flowers and pollinators were analysed statistically. Pollen counts following a series of floral manipulations were used to evaluate pollen dispensing efficiency and function of the anther appendages.

Key Results Field observations determined that two species of Bombus (bumble-bees) were the primary pollinators of I. arguta with a mean visiting frequency of 1.42 visitations …


Seasonal Adaptation Of Vegetation Color In Satellite Images, Srinivas Jakkula, Vamsi K.R. Mantena, Ramu Pedada, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.) Jan 2008

Seasonal Adaptation Of Vegetation Color In Satellite Images, Srinivas Jakkula, Vamsi K.R. Mantena, Ramu Pedada, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.)

Electrical & Computer Engineering Faculty Publications

Remote sensing techniques like NDVI (Normal Difference vegetative Index) when applied to phenological variations in aerial images, ascertained the seasonal rise and decline of photosynthetic activity in different seasons, resulting in different color tones of vegetation. The rise and fall of NDVI values decide the biological response, either the green up or brown down [1]. Vegetation in green up period appears with more vegetative vigor and during brown down period it has a dry appearance. This paper proposes a novel method that identifies vegetative patterns in satellite images and then alters vegetation color to simulate seasonal changes based on training …