Lucina floridana is an intertidal clam that contains intracellular, sulfur-oxidizing
symbiotic bacteria in its gills. These bacteria are chemolithoautotrophic, using the energy
from the oxidation of reduced sulfur compounds to power carbon fixation. Although
sulfide is an energy-rich compound, it is also toxic to aerobic metabolism and autooxidizes
in the...
This study quantified the frequency of simple versus
complex races of Puccinia striiformis Westend. in mixtures
of wheat cultivars possessing different race-specific
resistance genes. A simple race of a pathogen can infect
only one component, and a complex race of the pathogen can
infect two or more components of an...
A crucial factor in determining the accuracy of DNA replication is
maintenance of a balanced supply of deoxyribonucleoside triphosphates
(dNTPs) at replication forks. Perturbation of dNTP biosynthesis can
induce dNTP pool imbalance with deleterious genetic consequences,
including increased mutagenesis, recombination, chromosomal
abnormalities and cell death. Using the T4 bacteriophage system,...
Disease has been implied as an important selective
force acting in plant populations. This study was
conducted to determine the effects of stripe rust (Puccinia
striiformis) on the population dynamics of wheat (Triticum
aestivum) cultivar mixtures.
Five wheat cultivars were grown in pure stands and all
possible mixtures at three...
A static-renewal, seven day test was developed and
utilized to study the effects of nutrition on the sensitivity
of Mysidopsis intii Holmquist to zinc. It was found that
juvenile growth was the most reliable and sensitive endpoint
that could also reflect the subtle effects of low zinc
concentrations and diet...
Cephalosporium stripe of wheat (Triticum aestivum),
caused by the soilborne fungus Cephalosporium gramineum,
results in significant yield reductions in dryland winter
wheat crops of the U.S. Pacific Northwest. The
development of resistant cultivars offers the best hope
for disease control. Breeding for resistance is hampered
by the long trial times...
This thesis tests the hypothesis that innate immunity may be enhanced
immediately following a stressful event. The experiments characterize the acute
effects of the fight or flight response on some immunological and endocrine
parameters in rainbow trout (Oncorhynchus mykiss). Plasma cortisol and
catecholamines were elevated within seconds of the initiation...