naturally occurring insect growth regulators. ii. screening of insect and plant extracts as insect juvenile hormone mimics.ethereal extracts prepared from the larvae, pupae, or eggs of 10 species of insects and from various parts of 343 species of higher plants were screened for juvenilizing effects against tenebrio molitor and oncopeltus fasciatus. activity in both species was shown by an extract of the larvae of the stable fly, stomoxys calcitrans, whereas an extract of the pupae was active in o. fasiatus only. extracts of two plant species (echinacea angustifolia roots and chamaecyparis lawsoniana seeds) showed h ...19751221244
identification and characterization of rapd markers inferring genetic relationships among pine genomic dnas were extracted from several populations of pine species and amplified using oligonucleotides of random sequences. polymorphism in random amplified polymorphic dna (rapd) markers was high and sufficient in distinguishing each of the species. genetic relationships among eight pine species (pinus sylvestris, pinus strobus, pinus rigida, pinus resinosa, pinus nigra, pinus contorta, pinus monticola, and pinus banksiana) from different provenances were analyzed. the degree of band s ...200211908668
effects of phloem girdling in conifers on apical control of branches, growth allocation and air in wood.we investigated effects of stem phloem girdles on apical control of branch angle, stem and branch growth and stem air content in six conifer species. a stem girdle 2 cm above a branch caused the branch to bend upward in all six species. upward bending was associated with increased formation and action of compression wood (cw) in the lower portion of the branch. compression wood also formed in the main stem below the branch, suggesting increased auxin production in the branch. a stem girdle 2 cm ...200211960759
phosphate-limitation physiology in ectomycorrhizal pitch pine (pinus rigida) seedlings.foliar and root p concentrations, net h(2)po(4) (-) (p(i)) uptake rates, and root surface acid phosphatase (apase) rates were assessed in pitch pine (pinus rigida mill.) seedlings inoculated with the ectomycorrhizal fungi laccaria bicolor (maire) pat., paxillus involutus (batsch.) fr., or pisolithus tinctorius (pers.) coker and couch, and grown at 10 or 100 micro m p(i) in sand culture. following a 6-week period of acclimation to the p(i) regimes, seedlings grown at 100 micro m p(i) had greater ...199614871791
growth and nutrition of nonmycorrhizal and mycorrhizal pitch pine (pinus rigida) seedlings under phosphorus limitation.the association of ectomycorrhizal fungi with tree roots enhances the acquisition of phosphorus (p) from the soil. in addition to increasing the uptake of h(2)po(4) (-) (p(i)), mycorrhizal fungi may increase the spectrum of p sources utilized by tree roots by mediating the dissolution of insoluble metallophosphate salts or the hydrolysis of organic p compounds. to investigate the role of ectomycorrhizal fungi in enhancing p acquisition by tree roots, pitch pine (pinus rigida mill.) seedlings wer ...199314969894
phosphorus source alters host plant response to ectomycorrhizal diversity.we examined the influence of phosphorus source and availability on host plant (pinus rigida) response to ectomycorrhizal diversity under contrasting p conditions. an ectomycorrhizal richness gradient was established with equimolar p supplied as either inorganic phosphate or organic inositol hexaphosphate. we measured growth and n and p uptake of individual p. rigida seedlings inoculated with one, two, or four species of ectomycorrhizal fungi simultaneously and without mycorrhizas in axenic cultu ...200515809869
influence of meso- and microscale habitat structure on focal distribution of sympatric ixodes scapularis and amblyomma americanum (acari: ixodidae).we compared the distribution of sympatric ixodes scapularis say and amblyomma americanum (l.) within several suitable forested habitats at different spatial scales and characterized differences in microhabitat features accounting for the observed distribution of questing ticks. we used automatic data loggers placed in the shrub and litter layers to contrast mesoclimate and microclimate conditions experienced by questing ticks. larger numbers of i. scapularis were collected at sites where the for ...200515962776
growth and photosynthetic responses of two pine species (pinus koraiensis and pinus rigida) in a polluted industrial region in korea.we investigated the effects of pollutants on two pine species (pinus koraiensis and pinus rigida) in an industrial region in korea, using a physiological approach. the concentrations of fluorine (f) and chlorine (cl) in the atmosphere, in precipitation and soil water at the damaged site were all significantly higher than at a control site. moreover, the concentrations of f, cl and mn in pine needles were significantly higher, and essential elements and chlorophyll in needles were significantly l ...200616112781
hydraulic design of pine needles: one-dimensional optimization for single-vein leaves.single-vein leaves have the simplest hydraulic design possible, yet even this linear water delivery system can be modulated to improve physiological performance. we determined the optimal distribution of transport capacity that minimizes pressure drop per given investment in xylem permeability along the needle for a given length without a change in total water delivery, or maximizes needle length for a given pressure difference between petiole and needle tip. this theory was tested by comparativ ...200617087464
chronic gamma radiation affects the distribution of radial increment in pinus rigida stems.exposure of pitch pine trees to chronic ionizing radiation at rates between 1 and 5 roentgens per day for several years causes reduction of radial increment throughout the stem, the reduction being most ponounced near the base of the tree. both the size of the tree crown and climate influence the severity of the effect, trees with large crowns showing little effect at low exposures except in years of environmental stress.196317772083
distribution and hosts of callidiellum rufipenne (coleoptera: cerambycidae), an asian cedar borer established in the eastern united states.the distribution and hosts of the exotic cedar-boring beetle, callidiellum rufipenne (motschulsky) (coleoptera: cerambycidae), were determined in five northeastern u.s. states by capturing adults on cedar trap logs and by rearing adults from various conifers. this beetle was detected in the coastal states of massachusetts, rhode island, connecticut, new york, and new jersey. in these states, adults emerged from the live or dead wood of four genera and eight species of cupressaceae; species of pi ...200717849882
reconstructing holocene fire history in a southern appalachian forest using soil charcoal.lacking long-term dendrochronological and lake sediment data, little is known regarding the history of fire in southern appalachian forests through the holocene. here we used 82 radiocarbon ages for soil charcoal collected from local depositional sites along a topographic gradient from mixed hardwood (liriodendron tulipifera and quercus spp.) to oak-pine (quercus prinus and pinus rigida) forest to provide a coarse-grained picture of changes in fire frequency within a 10-ha area during the holoce ...201020426326
salt spray differentially affects water status, necrosis, and growth in coastal sandplain heathland species.sandplain heathlands are disturbance-dependent plant communities that occur infrequently in coastal areas of the northeastern united states. we hypothesize that salt spray plays a role in maintaining the composition of the heathland community by excluding salt-intolerant species close to the ocean. we examined the distributions of solidago nemoralis, myrica pensylvanica, pinus rigida, and quercus spp. in heathlands and conducted greenhouse studies to determine whether different levels of salt sp ...200321659219
sources of variation in growth, form, and survival in dwarf and normal-stature pitch pines (pinus rigida, pinaceae) in long-term transplant experiments.determining the relative contributions of genetic and environmental factors to phenotypic variation is critical for understanding the evolutionary ecology of plant species, but few studies have examined the sources of phenotypic differentiation between nearby populations of woody plants. we conducted reciprocal transplant experiments to examine sources of variation in growth rate, form, survival, and maturation in a globally rare dwarf population of pitch pine (pinus rigida) and in surrounding p ...200621642178
micromorphology of epicuticular waxes and epistomatal chambers of pine species by electron microscopy and white light scanning interferometry.high-resolution imaging and quantitative surface analysis of epicuticular waxes and epistomatal chambers of pine species were performed by field emission scanning electron microscopy and white light scanning interferometry. both juvenile and adult needles were collected from the two-year-old seedlings of pinus rigida and pinus densiflora and subjected to surface observations. epicuticular wax structures developed on the cuticle layer as well as in the epistomatal chambers and appeared to occlude ...201021087546
three-dimensional surface topography of the needle stomatal complexes of pinus rigida and its hybrid species by complementary microscopy.three-dimensional surface topography of needle stomatal complexes was investigated in pinus rigida, pinus taeda, and their interspecific hybrid pinus rigitaeda. the stomatal complexes of p. rigida appeared to be sunken and ca. 15 microm deep by white light scanning interferometry. stomatal grooves were evident in p. taeda along the stomata and amounted to ca. 5 microm deep. the centers of stomata maintained the similar height to the stomatal apertures. meanwhile, the stomatal complexes of p. rig ...201020452778
organosolv pretreatment with various catalysts for enhancing enzymatic hydrolysis of pitch pine (pinus rigida).three different types of catalysts were evaluated for organosolv pretreatment with pitch pine (pinus rigida). sulfuric acid, magnesium chloride, and sodium hydroxide for acid, neutral and base catalysts, respectively, were used, and ethanol was the organic solvent. the pretreatment process was conducted at different temperatures and times. the enzymatic hydrolysis process followed to estimate the digestibility of the biomass. the digestibility of pitch pine by pretreatment process with 1% sulfur ...201020435474
visualization of wound periderm and hyphal profiles in pine stems inoculated with the pitch canker fungus fusarium circinatum.postpenetration behavior of fusarium circinatum in stems of pine species was investigated with light and transmission electron microscopy. two-year-old stems of pinus rigida and p. densiflora were wound-inoculated with the fungal conidial suspension and subjected to 25 degrees c for up to 30 days. it was common to observe the formation of wound periderm on each pine species, recovering wounded sites with newly formed tissues. the outermost thick layer of wound periderm was pink to red colored wi ...200919484779
ectomycorrhizal responses to organic and inorganic nitrogen sources when associating with two host species.while it is established that increasing atmospheric inorganic nitrogen (n) deposition reduces ectomycorrhizal fungal biomass and shifts the relative abundances of fungal species, little is known about effects of organic n deposition. the effects of organic and inorganic n deposition on ectomycorrhizal fungi may differ because responses to inorganic n deposition may reflect c-limitation. to compare the effects of organic and inorganic n additions on ectomycorrhizal fungi, and to assess whether ho ...200919465124
responses of common and successional heathland species to manipulated salt spray and water availability.coastal sandplain heathlands are a rare plant community in the northeastern united states. salt spray and water availability are likely important factors determining heathland distribution. field surveys and manipulative experiments were performed to examine heathland species' responses to salt spray and water availability. we surveyed field distributions of four typical heathland species: solidago puberula, solidago rugosa, gaylussacia baccata, and myrica pensylvanica. the distributions of two ...200321653348
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