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Full-Text Articles in Life Sciences

Contents, Discovery Editors Jan 2003

Contents, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Propagation Of Thornless Arkansas Blackberries By Hardwood Cuttings, Mark Bray, Curt C. Rom, John R. Clark Jan 2003

Propagation Of Thornless Arkansas Blackberries By Hardwood Cuttings, Mark Bray, Curt C. Rom, John R. Clark

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Effects of auxin application and cutting location on canes on adventitious root development in hardwood cuttings of three Arkansas thornless blackberry cultivars were studied. Dormant canes were collected from one-year-old plants of ‘Apache’, ‘Arapaho’, and ‘Navaho’ and stored in a cold room until February. Two- or three-node cuttings were taken from the canes at apical, mid, and basal locations along the cane and were placed under intermittent mist in a perlite-filled greenhouse bed. Cuttings were either untreated or treated with auxin indole-3-butyric acid (IBA), applied as a liquid quick dip at 0.3%. In general, cutting diameter was greatest for basal …


Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 4 2003, Several Authors Jan 2003

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 4 2003, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Chitosanase May Enhance Anti-Fungal Defense Responses In Transgenic Tobacco, Bill L. Hendrix, James Mcd. Stewart Jan 2003

Chitosanase May Enhance Anti-Fungal Defense Responses In Transgenic Tobacco, Bill L. Hendrix, James Mcd. Stewart

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Chitosanase is an enzyme, similar to chitinase, capable of hydrolyzing the β-1,4-linkages between N-acetyl-D-glucosamine and D-glucosamine residues in partially acetylated chitosan polymers found in fungal cell walls. When attacked by pathogenic fungi, many plants exploit this hydrolytic action as a component of a larger post-attack defense response, but these enzymes may also play a role in the initial plant-pathogen interaction via the generation of elicitors resulting from the hydrolysis of fungal cell walls. To gain insight into these mechanisms, a Paenbacillus chitosanase was cloned, sequenced, and modified for plant expression. The modified gene was delivered to tobacco (Nicotiana tabacum L. …


Effect Of Triticum Turgidum Cytoplasm On Test Weight Of Soft Red Winter Wheat, Juan Mayta, Robert Bacon, John Kelly, Edward Gbur Jan 2003

Effect Of Triticum Turgidum Cytoplasm On Test Weight Of Soft Red Winter Wheat, Juan Mayta, Robert Bacon, John Kelly, Edward Gbur

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The effect of Triticum turgidum cytoplasm on soft red winter wheat (T. aestivum) was studied relative to test weight (bushel weight) and agronomic traits such as heading date, resistance to leaf rust, and plant color. The cytoplasmic effects were studied in three genetic backgrounds by crossing the cultivars Jackson, Pioneer 2684, and Wakefield with a plant introduction PI590277 that carried T. turgidum cytoplasm. Twelve alloplasmic and euplasmic populations were developed through a backcrossing procedure. The study used a micro test weight procedure to compare F4 lines within the populations for test weight. The data for other agronomic traits were taken …


Effects Of Virus Infection On Release Of Volatile Organic Compounds From Insect-Damaged Bean, Phaseolus Vulgaris, Sarah E. Sossamon, Britney K. Jackson, B. Alison Drumwright, Kenneth L. Korth, Gisela F. Erf Jan 2003

Effects Of Virus Infection On Release Of Volatile Organic Compounds From Insect-Damaged Bean, Phaseolus Vulgaris, Sarah E. Sossamon, Britney K. Jackson, B. Alison Drumwright, Kenneth L. Korth, Gisela F. Erf

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Insects can serve as important vectors of plant pathogens, especially viruses. Insect feeding on plants causes the systemic release of a wide range of plant volatile compounds that can serve as an indirect plant defense by attracting natural enemies of the herbivorous insect. Previous work suggests that the Mexican bean beetle (Epilachna varivestis) prefers to feed on plants infected by either of two viruses that it is known to transmit: Southern bean mosaic virus (SBMV) or Bean pod mottle virus (BPMV). A possible explanation for the preferred feeding on virus-infected tissues is that the beetles are attracted by volatile signals …


Instructions For Authors, Discovery Editors Jan 2003

Instructions For Authors, Discovery Editors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Letter From The Dean, Gregory J. Weidemann Jan 2003

Letter From The Dean, Gregory J. Weidemann

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


The Characteristics Of Consumers And Producers Using Farmers’ Markets, Walter Hugo Anez, Michael R. Thomsen Jan 2003

The Characteristics Of Consumers And Producers Using Farmers’ Markets, Walter Hugo Anez, Michael R. Thomsen

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

This study examines the perceptions of both consumers and producers towards farmers’ markets. Consumer perceptions are generalized from several previous studies conducted throughout the United States. Producer information was gathered through a survey of members of one farmers’ market in Arkansas. Previous studies, conducted in both rural and urban areas, indicate that the typical famers’ market customer is well educated and is of higher than average income. These consumers place great importance on quality of produce, knowledge that produce is grown locally, and the social interaction obtained through the farmers’ market experience. For producers, the farmers’ market is an important …


The Effects Of Potential Organic Apple Fruit Thinners On Gas Exchange And Growth Of Model Apple Trees: A Model Plant Study Of Transient Photosynthetic Inhibitors And Their Effect On Physiology And Growth, Jason D. Mcafee, Curt C. Rom Jan 2003

The Effects Of Potential Organic Apple Fruit Thinners On Gas Exchange And Growth Of Model Apple Trees: A Model Plant Study Of Transient Photosynthetic Inhibitors And Their Effect On Physiology And Growth, Jason D. Mcafee, Curt C. Rom

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Few fruit thinners have been certified for organic fruit growers. Previous studies have shown that herbicides or shade are capable of reducing photosynthesis and are effective fruit-thinning techniques, although impractical. This project evaluated use of a model plant system of vegetative apple trees grown under controlled conditions to study photosynthetic inhibitors, which could be used as potential organic thinning agents. Various concentrations of osmotics, salts, and oils (lime-sulfur, potassium bisulfite, potassium bicarbonate, sodium chloride, soybean oil) were applied to actively growing apple trees and showed a reduced trend on the rate of apple tree photosynthetic assimilation (Pn), evapotranspiration (Et), and …


Response Of Blackberry Cultivars To Nematode Transmission Of Tobacco Ringspot Virus, Alisha Sanny, John R. Clark, Rose Gergerich Jan 2003

Response Of Blackberry Cultivars To Nematode Transmission Of Tobacco Ringspot Virus, Alisha Sanny, John R. Clark, Rose Gergerich

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

A study was conducted on eight cultivars of blackberry (‘Apache’, ‘Arapaho’, ‘Chester’, ‘Chickasaw’, ‘Kiowa’, ‘Navaho’, ‘Shawnee’, and ‘Triple Crown’), of which four plants of each were previously determined in the fall of 2001 to have root, but not leaf, infection with Tobacco ringspot virus (TRSV). The objectives of our study were to determine virus effects on plant vigor and the spread of virus infection in the plants. Eight plants of each cultivar, four infected and four free of infection, were grown in pots on a gravel pad for the 2002 growing season, and samples of primocane and floricane leaves were …


Nuclear Ribosomal Its Region Sequences For Differentiation Of Rubus Genotypes, Eric T. Stafne, John R. Clark, Allen L. Szalanski Jan 2003

Nuclear Ribosomal Its Region Sequences For Differentiation Of Rubus Genotypes, Eric T. Stafne, John R. Clark, Allen L. Szalanski

Journal of the Arkansas Academy of Science

Previous molecular investigations into Rubus species diversity have yielded significant knowledge about species relatedness. However, little work has been focused at the cultivar level. Random amplified polymorphic DNA(RAPD)-PCR studies have successfully differentiated closely related cultivars. The ability to definitively distinguish blackberry and red raspberry cultivars based on other molecular methods could prove useful in many aspects of breeding and proprietary protection. In this study, the nuclear ribosomal DNA internal transcribed spacer regions (ITS) of six Rubus cultivars were sequenced. DNA sequencing revealed little genetic variation among blackberry cultivars, but revealed distinctions between blackberry and red raspberry cultivars. Analysis by maximum-parsimony …


On The Rare Endemic Hydrophyllum Brownei Kral & Bates (Browne's Waterleaf): New Population Information And A Recommendation For Change In Status, Travis D. Marsico Jan 2003

On The Rare Endemic Hydrophyllum Brownei Kral & Bates (Browne's Waterleaf): New Population Information And A Recommendation For Change In Status, Travis D. Marsico

Journal of the Arkansas Academy of Science

Hydrophyllum brownei Krai & Bates (Browne's waterleaf), newly described in 1991, is endemic to the Ouachita Mountain Natural Division of Arkansas. For the purpose of better understanding population parameters within which H. brownei grows, ranges of shade values, population extents, and population distance relationships to streams were measured. Hydrophyllum brownei grows in extremely high shade, in populations of widely varying sizes, and always in association with a stream system. In order to list species associated with H. brownei, vouchers of species assemblages were collected at the H. brownei sites visited. The species is designated as critically imperiled globally because of …