| comparative analysis of chloroplast dna in pyrus species: physical map and gene localization. | a physical map of chloroplast dna (cpdna) of pear [pyrus ussuriensis var. hondoensis (nakai et kikuchi) rehder] was constructed using five restriction enzymes, sali, xhoi, bamhi, saci and psti. this information will make it possible to investigate the phylogenetic relationships between pyrus species. pear cpdna was found to be a circular molecule with a total size of about 156 kb in which two inverted repeats of 24.8 kb divide the molecule into small (17 kb) and large (90 kb) single-copy regions ... | 2003 | 12582856 |
| role of sooty mold fungi in accumulation of fine-particle-associated pahs and metals on deciduous leaves. | the focus of this research was on elucidation of the role of deciduous tree ecosystems in accumulation of fine-particle-associated polycyclic aromatic hydrocarbons (pahs) and heavy metals on leaves of deciduous trees. the studied species were tilia x euchlora (frequently infested by sooty mold fungi) and pyrus calleryana (unaffected by sooty mold fungi). the selected species have similar leaf morphology and were exposed to identical environmental conditions. intra-species comparison showed that ... | 2006 | 16890933 |
| effect of host tree species on cellulase activity and bacterial community composition in the gut of larval asian longhorned beetle. | anoplophora glabripennis, the asian longhorned beetle, is a wood-boring insect that can develop in a wide range of healthy deciduous hosts and requires gut microbes to aid in wood degradation and digestion. here we show that larval a. glabripennis harbor a diverse gut bacterial community, and this community can be extremely variable when reared in different host trees. a. glabripennis reared in a preferred host (acer saccharum) had the highest gut bacterial diversity compared with larvae reared ... | 2009 | 19508777 |
| reproductive success of cultivated pyrus calleryana (rosaceae) and establishment ability of invasive, hybrid progeny. | • | 2010 | 21616803 |
| phylogeny and evolutionary histories of pyrus l. revealed by phylogenetic trees and networks based on data from multiple dna sequences. | reconstructing the phylogeny of pyrus has been difficult due to the wide distribution of the genus and lack of informative data. in this study, we collected 110 accessions representing 25 pyrus species and constructed both phylogenetic trees and phylogenetic networks based on multiple dna sequence datasets. phylogenetic trees based on both cpdna and nuclear lfy2int2-n (ln) data resulted in poor resolution, especially, only five primary species were monophyletic in the ln tree. a phylogenetic net ... | 2014 | 25083939 |
| differences in accumulation of pahs and metals on the leaves of tiliaxeuchlora and pyrus calleryana. | the accumulation of substances associated with pm2.5 [polycyclic aromatic hydrocarbons (pahs) and metals] on leaves of pyrus calleryana (pear) and tiliaxeuchlora (linden) along an urban road was investigated. these species have similar leaf morphology and were exposed to the identical environmental conditions. the accumulation of both pahs and metals per leaf area was significantly higher on linden leaves than on pear leaves. | 2002 | 12395847 |
| fluorescence shell: a novel view of sclereid morphology with the confocal laser scanning microscope. | confocal laser scanning microscopy (clsm) was used to observe sclereids from stems of avicennia germinans and from fruits of two species of pear (pyrus calleryana "bradford" and p. communis "red bartlett"). the images obtained from thick (25 to 100 microm) free-hand sections were, in certain respects, far superior to those obtained by other, more invasive and time-consuming microscopic techniques upon which previous reports of sclereid morphology were based. the cell wall surfaces, including the ... | 2004 | 15170758 |
| first record of the adventive oriental aphid schizaphis piricola (matsumura, 1917) (hemiptera, aphididae) in europe. | the oriental aphid schizaphis piricola (matsumura) is recorded for the first time in europe, on the ornamental pear tree pyrus calleryana in landscaped areas in madrid (spain). data on the morphology of the forms on primary host (apterous and alate fundatrigeniae and fundatrices), and their biology and distribution are given. the keys for identifying species of schizaphis (schizaphis) in the iberian peninsula are updated. two species of aphids are also recorded for the first time on pyrus caller ... | 2011 | 21594084 |
| relationship between woody plant colonization and typha l. encroachment in stormwater detention basins. | we studied stormwater detention basins where woody vegetation removal was suspended for 2 years in virginia, usa to determine if woody vegetation can control typha populations and how early woody plant succession interacts with typha, other herbaceous vegetation, and site factors. distribution and composition of woody vegetation, typha and non-typha herbaceous vegetation biomass, and site factors were assessed at 100 plots in four basins ranging in age from 7 to 17 years. a greenhouse study exam ... | 2013 | 23925899 |
| enhanced tolerance and accumulation of heavy metal ions by engineered escherichia coli expressing pyrus calleryana phytochelatin synthase. | contamination by heavy metals is a major environmental problem worldwide and microbial bioremediation is an efficient method for removing this type of pollution. the plant enzymephytochelatin synthase (pcs, also known as glutathione g-glutamylcysteinyltransferase, ec2.3.2.15) involved in the synthesis of phytochelatins (pcs), which are metal-binding cysteine-rich peptides, has a major role in the detoxification of heavy metals in plants. expression of the pcpcs1 gene from the bean pear (pyrus ca ... | 2015 | 25727053 |
| draft genome sequence of pseudomonas syringae pathovar syringae strain ff5, causal agent of stem tip dieback disease on ornamental pear. | pseudomonas syringae ff5 causes stem tip dieback disease on ornamental pear (pyrus calleryana). its genome encodes a complete type iii secretion system (t3ss) and hopac1, hopm1, avre1, hopi1, hopaa1, hopj1, hopah2, hopah1, hopag1, and hopaz1. lacking detectable homologues of other t3ss effectors, it may encode novel, undiscovered effectors. | 2012 | 22740663 |
| cydonia japonica, pyrus calleryana and p. amygdaliformis: three new ornamental or wild hosts of apple stem pitting virus. | japanese quince, ornamental and wild pear symptomless samples were infected with apple stem pitting virus (aspv). identification of aspv was achieved by different pcr assays that amplified either the rna polymerase or coat protein gene regions. for further confirmation, 312 bp amplicons within the polymerase gene were sequenced and compared with previously published aspv sequences and additional sequences of isolates from ancient italian cultivars. comparison of the partial sequences isolated fr ... | 2011 | 22006446 |
| quantitative resistance traits and suitability of woody plant species for a polyphagous scarab, popillia japonica newman. | the japanese beetle, popillia japonica newman, has an unusually broad host range among deciduous woody plants, yet it feeds only sparingly, or not at all, on certain species in the field. we evaluated beetles' preference, survival over time and fecundity on eight woody plant species historically rated as susceptible or resistant and, after verifying those ratings, tested whether resistance is correlated with so-called quantitative defense traits including leaf toughness, low nutrient content (wa ... | 2008 | 19161699 |
| transcriptome sequencing and analysis of major genes involved in calcium signaling pathways in pear plants (pyrus calleryana decne.). | pears (pyrus spp. l.) are an important genus of trees that produce one of the world's oldest fruit crops. salinity stress is a common limiting factor for plant productivity that significantly affects the flavor and nutritional quality of pear fruits. much research has shown that calcium signaling pathways, mediated by calcineurin b-like proteins (cbls) and their interacting kinases (cipks), are closely associated with responses to stresses, including salt. however, little is known about the mole ... | 2015 | 26424153 |
| transcriptome analysis of callery pear (pyrus calleryana) reveals a comprehensive signalling network in response to alternaria alternata. | the pear is an important temperate fruit worldwide that is produced by a group of species in the genus pyrus. callery pear (pyrus calleryana decne) is characterized by high resistance to multiple diseases, good adaptability, and high ornamental value, and is therefore widely planted in pear orchards for edible fruit production or as stock. plant pathogens are a major threat to pear yield. black spot disease, caused by the filamentous fungus alternaria alternata, is one of the most serious diseas ... | 2017 | 28934298 |
| thidiazuron (tdz) increases fruit set and yield of 'hosui' and 'packham's triumph' pear trees. | the low fruit set is one of the main factors leading to poor yield of pear orchards in brazil. the exogenous application of thidiazuron (tdz) and aminoethoxyvinilglycine (avg) has shown promising results in some pear cultivars and other temperate fruit trees. the objective of this study was to evaluate the effect of tdz and avg on fruit set, yield, and fruit quality of 'hosui' and 'packham's triumph' pears. the study was performed in a commercial orchard located in são joaquim, sc. plant materia ... | 2018 | 29267802 |
| glucose metabolism of various tissues of pear buds. | various tissues in flower buds of pyrus calleryana decne. differ in their metabolic activity. brown outer scales utilized more exogenously supplied glucose, particularly through the pentose phosphate pathway, than did the central axes and the green inner scales. they also contained more endogenous reducing sugars, and glucose leaked out more readily from the brown scales than from the other tissues. in contrast, respiration of the central axes was nine times as great as that of the brown scales, ... | 1970 | 16657553 |
| pear bud metabolism: seasonal changes in glucose utilization. | utilization of glucose, uracil and valine by flower and leaf buds of seedling pear trees (pyrus calleryana decne.) from the time of flower bud initiation to flowering was investigated. a very high rate of glucose utilization through the pentose phosphate pathway was observed throughout the development of buds. there was no difference in the type of glucose metabolism between flower and leaf buds except immediately before flowering, when the metabolism in flower buds was shifted toward the glycol ... | 1969 | 16657202 |
| eriophyoid mites from qinghai province, northwestern china with descriptions of nine new species (acari, eriophyoidea). | eriophyoid mites from qinghai province, northwestern china were studied herein. up to now, only six species have been reported from qinghai province. in field surveys, 17 eriophyoid mite species were collected, among which nine species were found new to science. the new species and their host plants are listed as follows: acaphyllisa tuberculumaesp. n. on populus sp. (salicaceae); proiectus xiningensissp. n. on pinus sp. (pinaceae); phyllocoptes beishaniensissp. n. on spiraea mongolica maxim. (r ... | 2012 | 22679390 |