| sequence signatures from dna amplification fingerprints reveal fine population structure of the dogwood pathogen discula destructiva. | isolates of discula destructiva redlin and an undescribed species of discula, the filamentous fungi that cause anthracnose of flowering (cornus florida l.) and pacific (cornus nuttalli aud.) dogwoods, were analyzed for genetic variation by nucleic acid scanning with arbitrary mini-hairpin oligonucleotide primers. while the fungal population was highly homogeneous throughout the disease range in eastern and western north america, the generation of arbitrary signatures from amplification profiles ... | 1996 | 8978092 |
| responses of plants to simulated saline drift as affected by species and conditions of exposure. | in exposures to simulated saline drift generated from a 0.6% (w/w) chloride (cl)-solution, under controlled environmental conditions, the median effective doses for the occurrence of any salt-induced foliar injury (expressed as microgcl cm(-2) deposited in six hours) were: 2.9 for canada hemlock (tsuga canadensis [l.] carr.); 10.3 for white flowering dogwood (cornus florida l.); 43.5 for potato (solanum tubersum l. cv superior); 44.2 for northern red oak (quercus rubra l.); 65.1 for sweet corn ( ... | 1991 | 15092146 |
| impacts of an exotic disease and vegetation change on foliar calcium cycling in appalachian forests. | because of the high calcium content of its foliage, cornus florida (flowering dogwood) has been described as a calcium "pump" that draws calcium from deeper mineral soil and enriches surface soil horizons. however, over the last two decades an exotic fungal disease (dogwood anthracnose, discula destructiva) has decimated populations of this once-common understory species. its loss, combined with forest stand development, could alter intra-stand calcium cycling. we used data from long-term vegeta ... | 2007 | 17494403 |
| freezing stress response in woody tissues observed using low-temperature scanning electron microscopy and freeze substitution techniques. | the objective of the current research was to examine the response of woody plant tissues to freezing stress by using scanning electron microscopy (sem). nonsupercooling species red osier dogwood (cornus stolonifera michx.), weeping willow (salix babylonica l.), and corkscrew willow (salix matsudana koidz. f. tortuosa rehd.) survived freezing stress as low as -60 degrees c. cell collapse of ray parenchyma cells of these species was expected but did not occur. it was concluded that ray parenchyma ... | 1991 | 16668066 |
| anthocyanins in cornus alternifolia, cornus controversa, cornus kousa and cornus florida fruits with health benefits. | the anthocyanins in native cornus alternifolia, cornus controversa, cornus kousa and cornus florida were quantified by hplc and characterized by spectroscopic methods. the analyses of c. alternifolia and c. controversa revealed that both contained , and , respectively. similarly, c. florida and c. kousa showed identical anthocyanin profiles with major anthocyanins as and cyanidin 3-o-glucoside (6), respectively. the amount of anthocyanins , and in c. alternifolia and c. controversa were 8.21, 8. ... | 2006 | 16139847 |
| estimates of net photosynthetic parameters for twelve tree species in mature forests of the southern appalachians. | leaf gas exchange, temperature, and incident radiation were measured in situ for 20 mature trees of 12 deciduous species spanning a range of heights from 7.9 to 30.1 m and growing in the southern appalachian mountains. air temperature, water vapor pressure, total radiation, photosynthetically active radiation, and carbon dioxide concentration were also measured. estimated mean, light-saturated net assimilation rates ( micro mol m(-2) s(-1)) were: quercus coccinea muenchh. (10.3), q. prinus l. (9 ... | 1996 | 14871725 |
| non-native ambrosia beetles as opportunistic exploiters of living but weakened trees. | exotic xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. we sought to characterize the role of host physiological condition on preference and colonization by two invaders, xylosandrus germanus and xylosandrus crassiusculus. when given free-choice under field conditions among flooded ... | 2015 | 26134522 |
| host race or species? allozyme characterization of the 'flowering dogwood fly', a member of the rhagoletis pomonella complex. | the term 'flowering dogwood fly' has been used in the literature for a poorly understood member of the rhagoletis pomonella sibling species complex infesting the fruits of flowering dogwood (cornus florida). electrophoretic analysis of 17 allozyme loci in 21 populations reveals significant frequency differences between the flowering dogwood fly and its closest relative the apple maggot fly, r. pomonella, and between it and the somewhat more distant 'sparkleberry fly'. frequency differences betwe ... | 1999 | 10651909 |
| foliar temperature-respiration response functions for broad-leaved tree species in the southern appalachians. | we measured leaf respiration in 18 eastern deciduous forest tree species to determine if there were differences in temperature-respiration response functions among species or among canopy positions. leaf respiration rates were measured in situ and on detached branches for acer pensylvanicum l., a. rubrum l., betula spp. (b. alleghaniensis britt. and b. lenta l.), carya glabra (mill.) sweet, cornus florida l., fraxinus spp. (primarily f. americana l.), liriodendron tulipifera l., magnolia fraseri ... | 1999 | 10562404 |
| genetic divergence along the speciation continuum: the transition from host race to species in rhagoletis (diptera: tephritidae). | studies of related populations varying in their degrees of reproductive isolation can provide insights into speciation. here, the transition from partially isolated host races to more fully separated sibling species is investigated by comparing patterns of genetic differentiation between recently evolved (∼150 generations) apple and ancestral hawthorn-infesting populations of rhagoletis pomonella to their sister taxon, the undescribed flowering dogwood fly attacking cornus florida. no fixed or d ... | 2013 | 24033167 |
| ecological genomics of local adaptation in cornus florida l. by genotyping by sequencing. | discovering local adaptation, its genetic underpinnings, and environmental drivers is important for conserving forest species. ecological genomic approaches coupled with next-generation sequencing are useful means to detect local adaptation and uncover its underlying genetic basis in nonmodel species. we report results from a study on flowering dogwood trees (cornus florida l.) using genotyping by sequencing (gbs). this species is ecologically important to eastern us forests but is severely thre ... | 2017 | 28070306 |
| analysis of two tfl1 homologs of dogwood species (cornus l.) indicates functional conservation in control of transition to flowering. | two tfl1 -like genes, corflotfl1 and corcantfl1 cloned from cornus florida and c. canadensis, function in regulating the transition to reproductive development in arabidopsis. terminal flower 1 (tfl1) is known to regulate inflorescence development in arabidopsis thaliana and to inhibit the transition from a vegetative to reproductive phase within the shoot apical meristem. despite the importance, tfl1 homologs have been functionally characterized in only a handful eudicots. here we report the ro ... | 2016 | 26825444 |
| components of water potential estimated from xylem pressure measurements in five tree species. | pressure volume curves were measured with a pressure bomb in leaves collected in the field from ilex opaca, acer rubrum, liquidambar styraciflua, liriodendron tulipifera and cornus florida. water potential components were calculated from the curves. the species differed in the relationships measured. in all species the trends from summer to fall were toward lower (more negative) osmotic potentials, lower matric potentials more rapid loss of turgor with increasing leaf water deficit, and the occu ... | 1977 | 28309017 |
| comparative photosynthesis of three gap phase successional tree species. | photosynthesis was measured in situ on trees growing in an open, gap-like site and under a closed canopy. photosynthetic responses also were monitored on trees grown in the laboratory under either a high or low light regime or on those trees transferred from a low to a high light regime. all three species studied, liriodendron tulipifera, acer rubrum and cornus florida, were able to acclimate to a high light environment as evidenced by their higher photosynthetic rates. this acclimation was achi ... | 1980 | 28309559 |
| seasonal patterns of leaf water relations in four co-occurring forest tree species: parameters from pressure-volume curves. | leaf water relationships were studied in four widespread forest tree species (ilex opaca ait., cornus florida l., acer rubrum l., and liriodendron tulipifera l.). the individuals studied all occurred on the same site and were selected to represent a range of growth forms and water relationships in some of the principal tree species of the region. the water relations of the species were analyzed using the concept of the water potential-water content relationship. the pressure-volume method was us ... | 1980 | 28310040 |
| nematode community structure in dogwood, maple, and peach nurseries in tennessee. | nursery blocks (48 dogwood, 27 maple, 17 peach) in 20 middle tennessee nurseries were sampled for nematodes in march,july, and october 1981. dogwoods and maples were grouped in three age classes: 1-2, 3-5, and 10+ years. nematodes were extracted from soil samples, counted, and assigned to trophic groups as follows: plant parasites, microbivores, fungivores, predators, and omnivores (= dorylaimida). total nematode numbers per 200 cm s soil ranged from 52 to 9,166 (mean = 1,785 +/- 1,420). nematod ... | 1985 | 19294070 |
| plant-parasitic nematode communities in dogwood, maple, and peach nurseries in tennessee. | nursery blocks (48 dogwood, 27 red maple, and 17 peach) distributed among 20 tennessee nurseries were sampled for nematodes in march, july, and october 1981. plant-parasitic nematodes were extracted from soil, counted by genera, and identified to species after fixation. a total of 57 species in 24 genera were found, with 1-16 species occurring in a site. the species most commonly detected were paratylenchus projectus and xiphinema americanum, which were found in 88% and 78% of the sites, respect ... | 1985 | 19294071 |
| intraspecific variation in production of astringent phenolics over a vegetation-resource availability gradient. | the chemical constituency of flowering dogwood (cornus florida l.) and red maple (acer rubrum l.) foliage was analyzed over a species compositional gradient to test the hypothesis that over subtle gradients of moisture and nutrient availability production of phenolic compounds will be increased on sites of greatest stress. calcium and nitrogen concentrations declined along the gradient in both species, while phosphorus showed a significant decline only in red maple. lignin concentrations in both ... | 1987 | 28311542 |
| patch size of forest openings and arthropod populations. | five sizes of canopy openings (0.016 ha to 10 ha) were established in the southern appalachian mountains in early 1982 to examine the initial patterns of plant and arthropod establishment across a size range of forest disturbances. vegetation standing crop after the first growing season was considerably higher in large than small openings in apparent response to greater resource release (e.g., sunlight) in larger openings. woody stump and root sprouts were the dominant mode of revegetation in ea ... | 1991 | 28312917 |
| gas exchange, leaf structure and nitrogen in contrasting successional tree species growing in open and understory sites during a drought. | seasonal ecophysiology, leaf structure and nitrogen were measured in saplings of early (populus grandidentata michx. and prunus serotina j.f. ehrh.), middle (fraxinus americana l. and carya tomentosa nutt.) and late (acer rubrum l. and cornus florida l.) successional tree species during severe drought on adjacent open and understory sites in central pennsylvania, usa. area-based net photosynthesis (a) and leaf conductance to water vapor diffusion (g(wv)) varied by site and species and were highe ... | 1995 | 14965944 |
| photosynthetic sunfleck utilization potential of understory saplings growing under elevated co2 in face. | few studies have evaluated elevated co2 responses of trees in variable light despite its prevalence in forest understories and its potential importance for sapling survival. we studied two shade-tolerant species (acer rubrum, cornus florida) and two shade-intolerant species (liquidambar styraciflua, liriodendron tulipifera) growing in the understory of a pinus taeda plantation under ambient and ambient+200 ppm co2 in a free air carbon enrichment (face) experiment. photosynthetic and stomatal res ... | 2000 | 28308370 |
| a six-year study of sapling and large-tree growth and mortality responses to natural and induced variability in precipitation and throughfall. | global climatic change may cause changes in regional precipitation that have important implications for forest growth in the southern united states. in 1993, a stand-level experiment was initiated on walker branch watershed, tennessee, to study the sensitivity of forest saplings and large trees to changes in soil water content. soil water content was manipulated by gravity-driven transfer of precipitation throughfall from a dry treatment plot (-33%) to a wet treatment plot (+33%). a control plot ... | 2001 | 11282574 |
| water relations of several hardwood species in response to throughfall manipulation in an upland oak forest during a wet year. | we investigated the effects of altered precipitation on leaf osmotic potential at full turgor (psi(pio)) of several species in an upland oak forest during the 1994 growing season as part of a throughfall displacement experiment at the walker branch watershed near oak ridge, tennessee. the main species sampled included overstory chestnut oak (quercus prinus l.), white oak (q. alba l.), red maple (acer rubrum l.); intermediates sugar maple (a. saccharum l.) and blackgum (nyssa sylvatica marsh.); a ... | 1998 | 12651369 |
| native leaf-tying caterpillars influence host plant use by the invasive asiatic oak weevil through ecosystem engineering. | we tested the effect of leaf-tying caterpillars, native ecosystem engineers, on the abundance and host feeding of an invasive insect, the asiatic oak weevil, cyrtepistomus castaneus (roelofs). leaf quality was previously thought to be the sole factor determining host use by c. castaneus, but adult weevils congregate in leaf ties made by lepidopteran larvae (caterpillars). adult weevil abundance was naturally higher on quercus alba and q. velutina compared to four other tree species tested (acer ... | 2014 | 25039212 |
| developing a media moisture threshold for nurseries to reduce tree stress and ambrosia beetle attacks. | exotic ambrosia beetles are among the most damaging pests of trees grown in nurseries. the primary pests xylosandrus crassiusculus motschulsky and xylosandrus germanus blandford use ethanol to locate vulnerable trees. research, primarily with x. germanus, has shown that flood-stressed trees emit ethanol and are preferentially attacked by ambrosia beetles. our goal was to develop a media (also called potting soil) moisture threshold as an integrated pest management (ipm) tactic and assess grower ... | 2016 | 27412195 |
| antiparasitic compounds from cornus florida l. with activities against plasmodium falciparum and leishmania tarentolae. | the objective of this study was to identify the antiplasmodial constituents from the bark of cornus florida l., a plant traditionally used in north america for the treatment of malaria. | 2012 | 22609155 |
| variable conductivity and embolism in roots and branches of four contrasting tree species and their impacts on whole-plant hydraulic performance under future atmospheric co₂ concentration. | anatomical and physiological acclimation to water stress of the tree hydraulic system involves trade-offs between maintenance of stomatal conductance and loss of hydraulic conductivity, with short-term impacts on photosynthesis and long-term consequences to survival and growth. here, we study the role of variations in root and branch maximum hydraulic specific conductivity (k(s-max)) under high and low soil moisture in determining whole-tree hydraulic conductance (k(tree)) and in mediating stoma ... | 2010 | 20566583 |
| association of nematodes and dogwood cankers. | dogwood canker is a serious production problem of unknown etiology. from may 1985 through april 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. seventy-three percent (213) of the cankers contained nematodes. panagrolaimus rigidus (schneider) thorne (115/290) and aphelenchoides spp. (91/290) were the most frequently collected taxa. panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. aphelenchoides spp ... | 1994 | 19279869 |
| the relationship between fire history and an exotic fungal disease in a deciduous forest. | exotic diseases have fundamentally altered the structure and function of forest ecosystems. controlling exotic diseases across large expanses of forest has proven difficult, but fire may reduce the levels of diseases that are sensitive to environmental conditions. we examined cornus florida populations in burned and unburned quercus-carya stands to determine if burning prior to anthracnose infection has reduced the impacts of an exotic fungal disease, dogwood anthracnose, caused by discula destr ... | 2008 | 18026756 |
| dynamics of bioluminescence by armillaria gallica, a. mellea and a. tabescens. | although fungal bioluminescence is well documented, the ecological significance is poorly understood. we examined bioluminescence by three sympatric species of armillaria wood decay fungi, differing in parasitic ability. luminescence by mycelia of four genets of a. gallica, a. mellea and a. tabescens was examined in response to environmental illumination or mechanical disturbance. luminescence dynamics were assessed in a time series of measurements every 2 min for 72 h for mycelia growing on mal ... | 2007 | 17883025 |
| flood stress as a technique to assess preventive insecticide and fungicide treatments for protecting trees against ambrosia beetles. | ambrosia beetles tunnel into the heartwood of trees where they cultivate and feed upon a symbiotic fungus. we assessed the effectiveness of flood stress for making cercis canadensis l. and cornus florida l. trees attractive to attack as part of insecticide and fungicide efficacy trials conducted in ohio and virginia. since female ambrosia beetles will not begin ovipositing until their symbiotic fungus is established within the host, we also assessed pre-treatment of trees with permethrin, azoxys ... | 2016 | 27548230 |
| freezing behaviours in wintering cornus florida flower bud tissues revisited using mri. | how plant tissues control their water behaviours (phase and movement) under subfreezing temperatures through adaptative strategies (freezing behaviours) is important for their survival. however, the fine details of freezing behaviours in complex organs and their regulation mechanisms are poorly understood, and non-invasive visualization/analysis is required. the localization/density of unfrozen water in wintering cornus florida flower buds at subfreezing temperatures was visualized with high-res ... | 2016 | 27497429 |
| an iridoid glucoside and the related aglycones from cornus florida. | a new iridoid glucoside, cornusoside a (1), and four new natural product iridoid aglycones, cornolactones a-d (2-5), together with 10 known compounds were isolated from the leaves of cornus florida. the structures of compounds 1-5 were established by interpretation of their spectroscopic data. cornolactone b (3) is the first natural cis-fused tricyclic dilactone iridoid containing both a five- and a six-membered lactone ring. a biosynthesis pathway is proposed for cornolactones c (4) and d (5), ... | 2014 | 25141901 |
| the gravity of pollination: integrating at-site features into spatial analysis of contemporary pollen movement. | pollen-mediated gene flow is a major driver of spatial genetic structure in plant populations. both individual plant characteristics and site-specific features of the landscape can modify the perceived attractiveness of plants to their pollinators and thus play an important role in shaping spatial genetic variation. most studies of landscape-level genetic connectivity in plants have focused on the effects of interindividual distance using spatial and increasingly ecological separation, yet have ... | 2014 | 24995799 |
| identification of fruit volatiles from green hawthorn (crataegus viridis) and blueberry hawthorn (crataegus brachyacantha) host plants attractive to different phenotypes of rhagoletis pomonella flies in the southern united states. | the apple maggot fly, rhagoletis pomonella, infests several hawthorn species in the southern usa. in a companion paper, we showed that r. pomonella flies infesting two different mayhaw species (crataegus opaca and c. aestivalis) can discriminate between volatile blends developed for each host fruit, and that these blends are different from previously constructed blends for northern fly populations that infest domestic apple (malus domestica), downy hawthorn (crataegus mollis), and flowering dogw ... | 2011 | 21887525 |
| analysis of genetic diversity in flowering dogwood natural stands using microsatellites: the effects of dogwood anthracnose. | flowering dogwood (cornus florida l.) populations recently have experienced severe declines caused by dogwood anthracnose. mortality has ranged from 48 to 98%, raising the concern that genetic diversity has been reduced significantly. microsatellite data were used to evaluate the level and distribution of genetic variation throughout much of the native range of the tree. genetic variation in areas affected by anthracnose was as high as or higher than areas without die-offs. we found evidence of ... | 2010 | 20820882 |
| haradamyces foliicola anam. gen. et sp. nov., a cause of zonate leaf blight disease in cornus florida in japan. | a fungus causing zonate leaf blight diseases in various evergreen and deciduous woody plant species in japan was characterized by a discoid multicellular propagule arising from a hyaline sclerotium-like structure in the leaf tissue and dark-coloured microconidia produced enteroblastically from the terminal cells on the surface of the discoid propagules. myrioconium-like microconidiophores also producing microconidia were occasionally produced in culture. no teleomorphic characteristics were obse ... | 2009 | 19028579 |
| emission of volatile chemicals from flowering dogwood (cornus florida l.) flowers. | reproduction of flowering dogwood trees occurs via obligate out-crossing, and u.s. native bees have been suggested to be primary pollinators of this ecologically and economically important deciduous tree. whether floral volatiles play a role in reproduction of the dogwood remains unclear. objectives of this study were to identify principal volatile chemicals emitted from dogwood flowers and to assess a temporal volatile emission profile and volatile consistency across four cultivars. inflorescen ... | 2008 | 18811168 |
| habitat avoidance: overlooking an important aspect of host-specific mating and sympatric speciation? | understanding speciation requires discerning how reproductive barriers to gene flow evolve between previously interbreeding populations. models of sympatric speciation for phytophagous insects posit that reproductive isolation can evolve in the absence of geographic isolation as a consequence of an insect shifting and ecologically adapting to a new host plant. one important adaptation contributing to sympatric differentiation is host-specific mating. when organisms mate in preferred habitats, a ... | 2005 | 16153040 |
| a two-generation analysis of pollen pool genetic structure in flowering dogwood, cornus florida (cornaceae), in the missouri ozarks. | anthropogenic landscape change can disrupt gene flow. as part of the missouri ozark forest ecosystem project, this study examined whether silvicultural practices influence pollen-mediated gene movement in the insect-pollinated species, cornus florida l., by comparing pollen pool structure (φ(st)) among clear-cutting, selective cutting, and uncut regimes with the expectation that pollen movement should be least in the uncut regime. using a sample of 1500 seedlings-10 each from 150 seed parents (4 ... | 2005 | 21652403 |
| postzygotic isolating factor in sympatric speciation in rhagoletis flies: reduced response of hybrids to parental host-fruit odors. | rhagoletis pomonella is a model for sympatric speciation (divergence without geographic isolation) by means of host-plant shifts. many rhagoletis species are known to use fruit odor as a key olfactory cue to distinguish among their respective host plants. because rhagoletis rendezvous on or near the unabscised fruit of their hosts to mate, behavioral preferences for fruit odor translate directly into premating reproductive isolation among flies. here, we report that reciprocal f(1) hybrids betwe ... | 2004 | 15591346 |
| identification of host fruit volatiles from flowering dogwood (cornus florida) attractive to dogwood-origin rhagoletis pomonella flies. | solid-phase microextraction and gas chromatography coupled with electroantennographic detection were used to identify volatiles from fruit of flowering dogwood, cornus florida, as key attractants for rhagoletis pomonella flies originating from dogwood fruit. a six-component blend containing ethyl acetate (54.9%), 3-methylbutan-1-ol (27.5%), isoamyl acetate (0.9%), dimethyl trisulfide (1.9%), 1-octen-3-ol (9.1%), and beta-caryophyllene (5.8%) was identified from flowering dogwood fruit that gave ... | 2003 | 14682516 |
| a comparison of root growth dynamics of silver maple and flowering dogwood in compacted soil at differing soil water contents. | many bottomland tree species are tolerant of compacted soil and perform well in urban environments; however, the mechanism underlying this tolerance is unknown. increased soil water content has been shown to alleviate some of the effects of soil compaction on plant growth, presumably because increasing soil water reduces soil strength. we hypothesized that tree species tolerant of very wet soils would have opportunities for root growth in compacted soil when high soil water contents reduced soil ... | 2000 | 12651462 |
| osmotic potential of several hardwood species as affected by manipulation of throughfall precipitation in an upland oak forest during a dry year. | components of dehydration tolerance, including osmotic potential at full turgor (psi(pio)) and osmotic adjustment (lowering of psi(pio)), of several deciduous species were investigated in a mature, upland oak forest in eastern tennessee. beginning july 1993, the trees were subjected to one of three throughfall precipitation treatments: ambient, ambient minus 33% (dry treatment), and ambient plus 33% (wet treatment). during the dry 1995 growing season, leaf water potentials of all species decline ... | 1998 | 12651368 |
| solute accumulation of chestnut oak and dogwood leaves in response to throughfall manipulation of an upland oak forest. | to determine the biochemical basis of osmotic adjustment, seasonal and treatment differences in foliar water- soluble organic solutes and inorganic ions were investigated for two hardwood species that exhibited osmotic adjustment in a throughfall displacement experiment at the walker branch watershed near oak ridge, tennessee. leaf samples of overstory and understory chestnut oak (quercus prinus l.) and understory dogwood (cornus florida l.) were collected during the 1994 (wet) and 1995 (dry) gr ... | 2002 | 11874721 |
| patterns of evolution in discula fungi and the origin of dogwood anthracnose in north america, studied using arbitrarily amplified and ribosomal dna. | the anthracnose epidemic caused by exotic filamentous fungi of the genus discula threatens the future of the prized flowering (cornus florida l.) and pacific (c. nuttalli aud.) dogwoods in north america. a cross-section of fungi that cause anthracnose in broadleaf temperate trees was characterized using dna amplification fingerprinting, sequence and secondary structure analysis of the internal transcribed spacers (its) of nuclear ribosomal dna (rdna), and compatibility of hyphal anastomosis. its ... | 2001 | 11525409 |
| dogwood borer (lepidoptera: sesiidae) infestation of horned oak galls. | pin oak, quercus palustris muenchhausen, is the primary host for the gall wasp callirhytis cornigera (osten sacken). woody stem galls formed by c. cornigera may be infested by the dogwood borer, synanthedon scitula (harris), an important pest of flowering dogwood, cornus florida l. previous research has shown that s. scitula has a bimodal seasonal flight pattern, with peaks in late spring and midsummer. we tested the hypothesis that moths emerging from dogwoods largely account for the first flig ... | 2000 | 10902327 |
| plant cuticle staining with bismarck brown y and azure b or toluidine blue o before paraffin extraction. | transverse paraffin sections of mature greenwood stems of rose (rosa x hybrida) and flowering dogwood (cornus florida l.) were stained with bismarck brown followed by azure b or toluidine blue 0. the bismarck brown was replaced by thiazin dye metachromasia in all structures except the cuticle which remained brown or yellow. the interface between the cuticle and exterior cell walls of the epidermis was delineated clearly. | 1996 | 9138538 |
| ultrastructural evidence that intracellular ice formation and possibly cavitation are the sources of freezing injury in supercooling wood tissue of cornus florida l. | although cellular injury in some woody plants has been correlated with freezing of supercooled water, there is no direct evidence that intracellular ice formation is responsible for the injury. in this study we tested the hypothesis that injury to xylem ray parenchyma cells in supercooling tissues is caused by intracellular ice formation. the ultrastructure of freezing-stress response in xylem ray parenchyma cells of flowering dogwood (cornus florida l.) was determined in tissue prepared by free ... | 1993 | 12231977 |
| the effect of anthracnose (discula destructiva) infection on plant-herbivore interactions in dogwood (cornus florida). | the natural occurrence of dogwood anthracnose (discula destructiva) on young dogwood seedlings planted in different microenvironments in the southern appalachian mountains provided an opportunity to examine the effects of biotic stress on phenolic defense and insect herbivory. dogwood trees planted in forest understory, canopy gaps, and along forest edge sustained high levels of infection and mortality. in contrast, trees planted in full sun and under shade cloth in an adjacent open field sustai ... | 1993 | 28313760 |
| mediation of deep supercooling of peach and dogwood by enzymatic modifications in cell-wall structure. | treatment of stem sections of peach (prunus persica (l.) batsch) and flowering dogwood (cornus florida l.) with macerase, an enzyme mixture rich in pectinase, for 24-48 h resulted in a complete flattening of the low-temperature exotherm (lte) as determined by differential thermal analysis (dta). ultrastructural analysis of macerase-treated tissue demonstrated a nearly complete digestion of the pit membrane (black cap and primary cell-wall) of nearly 100% of the xylem-parenchyma cells examined af ... | 1991 | 24194078 |
| somatic embryogenesis and plantlet regeneration in cornus florida. | somatic embryos were initiated from 12 to 15 weeks postanthesis (wpa) zygotic embryos of cornus florida l. (flowering dogwood) cultured on murashige-skoog (ms) or schenk and hildebrandt (sh) medium amended with either 3 mg/l 2,4-d or 5 mg/l 2,4-d and 1 mg/l kinetin. white, opaque globular and early cotyledonary stage embryos were formed directly on detached cotyledons from 2 of the 5 trees sampled after 7 weeks of culture. morphologically mature embryos developed after an additional 4 weeks incu ... | 1989 | 24233223 |
| foliar nutrient dynamics and nutrient use efficiency in cornus florida. | growth rates and seasonal changes in foliar nitrogen, phosphorus, and calcium of cornus florida l. (flowering dogwood) individuals were determined in three forest stands which differed in soil moisture and soil nutrient availability. nutrient use efficiency of individual trees was measured by amount of leaf dry mass produced per unit nutrient invested, rates of nutrient resorption prior to litterfall, wood and leaf mass produced per unit nutrient turnover (=growth efficiency), projected uptake n ... | 1985 | 28310804 |
| osmotic factors of dehardening in cornus florida l. | the killing temperature for cortical cells from the flowering dogwood changes abruptly from -25 c to -15 c during dehardening. cell sap concentration, minimum critical cell volume, and osmotically inactive cell volume show a progressive change during dehardening, but only cell sap concentration is correlated directly with the killing temperature, showing the same step change. there is a limit to the extent to which hardy dogwood cells can be osmotically reduced in volume. beyond this limiting vo ... | 1976 | 16659656 |
| evolution of bract development and b-class mads box gene expression in petaloid bracts of cornus s. l. (cornaceae). | despite increasing interest in the molecular mechanisms of floral diversity, few studies have investigated the developmental and genetic bases of petaloid bracts. this study examined morphological patterns of bract initiation and expression patterns of b-class mads-box genes in bracts of several cornus species. we suggest that petaloid bracts in this genus may not share a single evolutionary origin. developmental pathways of bracts and spatiotemporal expression of b-class genes in bracts and flo ... | 2012 | 22897242 |