Plant hormones regulate progression through the different phases of plant development in response to endogenous and environmental cues. Gene expression studies, as well as genetic and molecular analysis of mutants with altered hormonal responses, are two common approaches to elucidate hormone response pathways. This dissertation compares ovary and fruit development...
The effect of planting density and nitrogen (N) fertilization on growth, yield, and N partitioning in young and mature 'Bluecrop' blueberry plants was studied over a two year period. Depleted 15N-ammonium sulfate was applied at different rates and on different dates in a mature planting, and at different rates in...
1-Phenyl-3-(2-Thiazoly1)-2-Thiourea (PTTU), has been reported to
inhibit dopamine-fi-hydroxylase (a copper-containing enzyme involved in
the pathway of biosynthesis of adrenaline in animal systems). In the
present study, PTTU has been shown to have cytokinin activity in the
tobacco bioassay. The cytokinin activity of PTTU suggested that
cytokinin-active N⁶-substituted adenine derivatives might...
To understand the effect of human-induced stresses on forests, there is a need for a method to separate effects of imposed stress from effects of natural climate stress. I developed an approach to predict forest response to climate stress using as indicators stable carbon isotopes in tree foliage and growth-rings....
Two studies used DNA markers to assess their usefulness in germplasm identification and evaluation of genetic stability in four cryopreserved Rubus accessions that were stored for over 10 years in liquid nitrogen. In the first study, 12 robust Simple Sequence Repeat (SSR) markers were developed from two microsatellite-enriched libraries of...
Poplar Bark Storage Proteins (BSP) are important in storing nitrogen (N)
recovered from autumn-senescent leaves, and supply N for spring growth. Plants of
Populus tremula x P. alba were transformed with a poplar BSP antisense cDNA
fused to a double 35S promoter. Regenerated lines were screened for reduced BSP
accumulation...
Container grown pear trees were used to determine the effects of the following factors on the susceptibility to Phytophthora syringae: 1) tree nitrogen (N) status and foliar sprays of urea and copper-EDTA (CuEDTA); 2) dormancy and environmental conditions; 3) wound and wound age; and 4) chemical and biological control measures....
The auxin-resistant diageotropica (dgt) mutant of tomato (Lycopersicon esculentum Mill.) has a pleiotropic phenotype including a lack of lateral roots and reduced gravitropic response, apical dominance, vascular development, and fruit growth. The dgt mutation reduces the auxin sensitivity of only a subset of auxin responses while levels, metabolism, and transport...
The photosynthetic activities, the pigmentation and the chloroplast
membrane polypeptides of several mutants of the green alga, Scenedesmus
obliquus, with complete or limited deficiencies in the light-harvesting
complex of photosystem II are characterized and compared to those of the
normal phenotype.. The principal phenotype examined in this study, K0 -9,...
Pollen development is an important process in male flower development, the timing of which may be correlated with time of pollen shed in hazelnut (Corylus avellana L.). Early to very late blooming cultivars were identified and the relationship of microsporogenesis and microgametogenesis, and time of pollen shed were studied in...
'Gala' is an apple cultivar with a distinctive aroma and flavor. 'Gala' storage season is short in regular atmosphere (RA). Controlled atmosphere (CA) extends 'Gala' storage but volatile production is reduced. 'Gala' odor-active aroma compounds were identified using Osme, a gas chromatography and olfactometry technique. Changes in aroma after RA...
A series of four studies were conducted in Colombia, South America,
in the field and the greenhouse to determine the effect of plant
competition and mulching on carbohydrate and photosynthate distribution
and nitrogen fixation in beans (Phaseolus vulgaris L.).
Mulching beans (determinant growth habit) with rice hulls in the
lowland...
Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI)...