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1

Greenaway, W., S. English, J. May, and F. R. Whatley. "Analysis of Phenolics of Bud Exudates of Populus cathayana and Populus szechuanica by GC-MS." Zeitschrift für Naturforschung C 47, no. 3-4 (April 1, 1992): 308–12. http://dx.doi.org/10.1515/znc-1992-3-423.

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Анотація:
Abstract Analysis of GC-MS data revealed 58 com ponents of bud exudate from P. cathayana (Section Tacamahaca) and 40 components of bud exudate from P. szechuanica (Section Tacamahaca) of which 47 and 35 respectively were phenolics. The bud exudates were very similar in composition, containing flavanones and chalcones (61% and 51% respectively), flavones (15% and 12%) and pentenyl caffeates (11% and 6%). The major single component of the exudate of both poplars was pinobanksin- 3-acetate (26% and 33%). The bud exudates of P. cathayana and P. szechuanica are similar to those of European and American Section Aigeiros poplars and unlike those of North American Section Tacamahaca poplars.
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2

Greenaway, W., J. May, and F. R. Whatley. "Notes: Analysis of Phenolics of Bud Exudate of Populus laurifolia by GC-MS." Zeitschrift für Naturforschung C 47, no. 9-10 (October 1, 1992): 776–78. http://dx.doi.org/10.1515/znc-1992-9-1023.

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Analysis by GC-MS identified 30 phenolic components of the bud exudate of P. laurifolia. The majority of the exudate was composed of flavanones, flavanonols and chalcones, with pinobanksin-3-acetate being the major component. The bud exudate resembled that of the Asian Section Tacamahaca poplars P. cathayana and P. szechuanica but was unlike that of the North American Section Tacamahaca poplars, P. balsamifera and P. trichocarpa.
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3

Gom, Lori A., and Stewart B. Rood. "Fire induces clonal sprouting of riparian cottonwoods." Canadian Journal of Botany 77, no. 11 (January 30, 2000): 1604–16. http://dx.doi.org/10.1139/b99-135.

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The principal native trees in the semiarid regions of southern Alberta are riparian cottonwoods. These include narrowleaf cottonwood, Populus angustifolia James, balsam poplar, Populus balsamifera ssp. balsamifera L., black cottonwood, Populus balsamifera ssp.trichocarpa Torr. & Gray, and prairie cottonwood, Populus deltoides Bartr., and interspecific hybrids. These phreatophytic poplars occur on the moist floodplains along streams and require flood disturbance for seedling recruitment. The present study investigated the responses of cottonwoods to another physical disturbance, fire. Two fires occurred in April 1992, in adjacent groves along the Oldman River at Lethbridge, Alberta. The fires occurred prior to bud flushing and the cottonwoods responded by vigorous sprouting, particularly in the first summer. By September of 1992 about 75% of the burned trees had produced coppice sprouts, new shoots from the remnant stumps. Root suckers, adventitious shoots from the roots of the burned trees, were also common, averaging 1 sucker/3 m2 in the burned zone. Five years after the burns, the number of clonal sprouts was reduced by about half and those had reached an average height of 3 m. Because of the difficulties of species identification for juvenile cottonwoods, sprouts were designated as Populus section Aigeiros (P. deltoides) or section Tacamahaca (the other species). After 5 months, 90% of the sprouting trunks and 80% of the suckers belonged to section Tacamahaca. After 5 years, this ratio had increased to 97% of the sprouting trunks and 98% of the suckers. This indicates that Tacamahaca cottonwoods produced more numerous sprouts with better survival than P. deltoides. This pattern across Populus sections was also observed at seven other cottonwood burn sites in western North America, from northern British Columbia to southern Utah. The Aigeiros cottonwoods, P. deltoides and P. fremontii S. Wats., produced few clonal shoots following fire, whereas Tacamahaca trees sprouted profusely. This study demonstrates that fire disturbance can stimulate clonal regeneration of riparian cottonwoods, particularly of section Tacamahaca.
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4

Floate, Kevin D. "Extent and patterns of hybridization among the three species of Populus that constitute the riparian forest of southern Alberta, Canada." Canadian Journal of Botany 82, no. 2 (February 1, 2004): 253–64. http://dx.doi.org/10.1139/b03-135.

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Анотація:
Three species of Populus (Salicaceae) overlap and hybridize in southern Alberta, Canada. Variation in leaf morphology throughout the region identifies five genetically distinct zones. The drainage of the Oldman River contains a pure zone of balsam poplar (Populus balsamifera L.), a pure zone of plains cottonwood (Populus deltoides Marsh.), plus overlap and hybrid zones of balsam poplar – narrowleaf cottonwood (Populus angustifolia James) and balsam poplar – narrowleaf cottonwood – plains cottonwood. The drainage of the Red Deer River contains a pure zone of balsam poplar, a pure zone of plains cottonwood, plus an overlap and hybrid zone of balsam poplar – plains cottonwood. Zones on both drainages coincide with an elevational gradient. Overlap and hybrid zones extend at least 700 river km (the length obtained by measuring distances between sites of hybridization on a river and its tributaries) combined across the two drainages. Principal components analyses on leaf morphology identify a pattern of bidirectional intro gression between sect. Tacamahaca (balsam poplar, narrowleaf cottonwood) species. These analyses also identify a pattern of unidirectional introgression between Tacamahaca and sect. Aigeiros (plains cottonwood) species, with F1 hybrids backcrossing only with the Tacamahaca parent. This pattern of unidirectional introgression subsequently was assessed and supported with data from the drainages of Ashley Creek and the Ogden River, Utah, which contain hybrid and overlap zones between narrowleaf cottonwood (Tacamahaca) and Fremont cottonwood, Populus fremontii S. Watson (Aigeiros). Given its unique nature in terms of extent, health, and composition, and given the effect of plant hybrid zones on the ecology and evolution of their associated organisms, it is hoped that the current study will facilitate future research targeting conservation of this riparian forest in its full genetic complexity.Key words: Populus, hybridization, riparian, cottonwood, introgression.
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5

Greenaway, W., S. English, J. May, and F. R. Whatley. "Analysis of Phenolics of Bud Exudates of Populus koreana, Populus maximowiczii and Populus suaveolens by GC-MS." Zeitschrift für Naturforschung C 47, no. 3-4 (April 1, 1992): 313–17. http://dx.doi.org/10.1515/znc-1992-3-424.

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Анотація:
Abstract Analysis of GC-MS data revealed 76 components of bud exudates from Populus koreana, P. maximowiczii and P. suaveolens (Section Tacamahaca), of which 49 were phenolics. The bulk of the exudates were composed of phenones, pinobanksin-3-acetate and aliphatic esters of caffeic acid. Bud exudates of P. koreana and P. m aximowiczii were virtually identical in composition and closely resembled those of P. suaveolens. The three poplars were alike in having as major com ponents of their bud exudate pentanophenones, which do not occur in the bud exudates of most other poplars. These three Asiatic poplars appear more closely related chemotaxonomically to Section Aigeiros poplars than to those of Section Tacamahaca.
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6

English, S., W. Greenaway, and F. R. Whatley. "Bud exudate composition of Populus tremuloides." Canadian Journal of Botany 69, no. 10 (October 1, 1991): 2291–95. http://dx.doi.org/10.1139/b91-288.

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Анотація:
Gas chromatography – mass spectrometry analysis of the bud exudate of seven specimens of Populus tremuloides (section Leuce) revealed a different chemical composition from that previously observed for poplars of sections Aigeiros and Tacamahaca. The bud exudate consists of three principal groups of compounds; benzoic and phenylpropenoic acids and their esters, the flavanones isosakuranetin and sakuranetin and their corresponding chalcones, and hydrocarbons. The flavonoids characteristic of section Aigeiros and section Tacamahaca poplars were found to be either missing, as in the case of flavanonols and dihydrochalcones, or present in very small amounts. The seven specimens of P. tremuloides analysed were classified into three categories depending on the relative proportions of these three groups of compounds present in their bud exudate, and the exudate composition was compared with that of four specimens of Populus grandidentata analysed. Key words: Populus tremuloides, bud exudate, gas chromatography – mass spectrometry.
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7

Nasimovich, Yuri, Marina Kostina, and Natalia Vasilieva. "The concept of species in poplars (genus Populus L., Salicaceae) based on the example of the subgenus Tacamahaca (Spach) Penjkovsky representatives growing in Russia and neighbouring countries." SOCIALNO-ECOLOGICHESKIE TECHNOLOGII 9, no. 4 (2019): 426–66. http://dx.doi.org/10.31862/2500-2961-2019-9-4-426-466.

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Анотація:
Using the traditional research methods, based on the example of local and cultivated representatives of the Tacamahaca (Spach) Penjkovsky subgenus growing in Russia and neighboring countries, the concept of a species in poplars (genus Populus L., Salicaceae) has been developed. It is suggested that the sections of black poplars (Aigeiros Duby) and balsamic poplars (Tacamahaca Spach) in Eurasia form a single supraspecific system with a common gene pool, which is very similar to syngameon. The taxonomic species that make up such a system are different dynamic states of this system and exist in the equilibrium state between natural selection, which forms and preserves the specifics of each dynamic state, and gene flows from other taxonomic species. Such a system can also be considered as a large Linnaean species represented by many subspecies or even geographical and ecological races. The use of molecular genetic methods for the taxonomic species study in the Populus genus is difficult due to the powerful flow of genes between the species, since the species differ in a small number of genes responsible for adaptive characters. The sections of the subgenus Tacamahaca poplars are ecological. The combination of species in these sections is not so much about the unity of their origin, but about the common growing conditions: black poplars tend to grow in lowlands, while the balsamic poplars tend to grow in the mountains, with which the poplars’ diagnostic characters are associated. In nature, belonging to a certain section is more profitable than the intermediate state, but in cultivation and in the urban environment, the opposite situation is observed.
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8

Le Coz, Christophe-J. "Allergic contact dermatitis from tamanu oil (Calophyllum inophyllum, Calophyllum tacamahaca)." Contact Dermatitis 51, no. 4 (October 2004): 216–17. http://dx.doi.org/10.1111/j.0105-1873.2004.0424h.x.

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9

Marquina-Chidsey, Germania, Brandfort Monro, Ingrid Velázquez, Daniel Arias, Eliana Pérez, Diego T. Santos, and Maritza Vargas. "Evaluation of supercritical fluid extraction of tacamahaco (Protium heptaphyllum) resin." Journal of Essential Oil Research 29, no. 6 (August 16, 2017): 443–50. http://dx.doi.org/10.1080/10412905.2017.1360217.

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10

Zsuffa, Louis, Dolly Lin, and Peggy Payne. "One-way crossing barriers in some interspecific crosses of Aigeiros and Tacamahaca poplars." Forestry Chronicle 75, no. 5 (October 1, 1999): 833–36. http://dx.doi.org/10.5558/tfc75833-5.

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Анотація:
New evidence is described on one way crossing barriers between Aigeiros and Tacamahaca species, gained in experimental full-sib crosses. The technique of crosses and embryo rescue are described. In some crosses of questionable result, the embryo rescue was successful. The possible genetic mechanisms underlying the crossing barriers are discussed. Key words: Populus, hydridization, embryo rescue, crossing barriers
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11

Guo, Liqin, Wenting Xu, Yan Zhang, Jinfeng Zhang, and Zunzheng Wei. "Inducing triploids and tetraploids with high temperatures in Populus sect. Tacamahaca." Plant Cell Reports 36, no. 2 (November 17, 2016): 313–26. http://dx.doi.org/10.1007/s00299-016-2081-0.

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12

Nasimovich, Yuri, and Natalia Vasilieva. "Comparison of morphological characters of different poplar species (Populus, Salicaceae) using the example of Russian and Central Asian Tacamahaca (Spach) Penjkovsky subgenus representatives." SOCIALNO-ECOLOGICHESKIE TECHNOLOGII 9, no. 3 (2019): 285–301. http://dx.doi.org/10.31862/2500-2961-2019-9-3-285-301.

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Анотація:
Statistical analysis of 10 quantitative and 9 qualitative diagnostic characters of leaves and shoots of three Russian (Populus laurifolia Ledeb., P. nigra L., P. suaveolens Fisch.) and two Central Asian (P. usbekistanica Komarov, P. macrocarpa (Schrenk.) N. Pavl. et Lipsch.) poplar species of the Tacamahaca (Spach) Penjkovsky subgenus was performed. It was shown that according to studied quantitative characters P. nigra (Aegirus section) and P. suaveolens (Tacamahaca section) belong to opposite “poles”. This could be possibly due to the fact that the first species is the most common for lowlands poplar in said group, and the second species is the most mountainous and confined to the most severe climatic conditions. The natural areas of these two species are also geographically extremely far from one another. The other three species occupy an intermediate position both in their characters, in terms of growth, and geographically. In addition, they all hybridize in nature with Populus nigra, and Populus laurifolia also with P. suaveolens, which can also explain the intermediate nature of their characters. It was shown that the leaf characters, such as leaf length and width, leaf length and width ratio etc., reflect the specificity of the studied species somewhat worse than a number of specific characters (leaf maximum width position, leaf teeth height and lateral edge radius of curvature, leaf top length and width).
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13

Kalischuk, Andrea R., Lori A. Gom, Stewart B. Rood, and Kevin D. Floate. "Intersectional cottonwood hybrids are particularly susceptible to the poplar bud gall mite." Canadian Journal of Botany 75, no. 8 (August 1, 1997): 1349–55. http://dx.doi.org/10.1139/b97-847.

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The occurrence of hybrid breakdown, the poor performance of certain hybrids, was investigated in cottonwoods (Populus) with respect to susceptibility to the poplar bud gall mite, Aceria parapopuli. The abundance of mite galls was investigated for all 352 cottonwoods on an island at Lethbridge, Alberta, where a natural trispecific hybrid swarm involves the narrowleaf cottonwood (Populus angustifolia) and the balsam poplar (Populus balsamifera) of section Tacamahaca and the prairie cottonwood (Populus deltides) of section Aigeiros. There, 78% of the intersectional hybrids (i.e., P. deltoides × P. angustifolia or P. balsamifera), 56% of the intrasectional (P. angustifolia × P. balsamifera) hybrids, and 36% of the single-species trees displayed some galls. Nine percent were heavily infested, and these were almost all intersectional hybrids. At four other riparian sites in British Columbia and Alberta with only single species or the two Tacamahaca cottonwoods, very few galls were observed and no trees were severely infested. Conversely, artificially planted intersectional hybrids near all sites displayed severe infestations, confirming the occurrence of mites throughout the region and the susceptibility of intersectional hybrids. The susceptibility to pests probably hinders growth and reproduction and thus disfavors the intersectional hybrids. Since hybrid poplars are widely planted for horticultural or silvicultural applications, this study suggests that future selections should consider the vulnerability of hybrids and especially intersectional hybrids to insect pests. Key words: Populus, insect pests, cottonwoods, galls, hybrids, riparian vegetation.
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14

Assibi Mahama, A., Richard Hall, and Ronald Zalesny. "Differential interspecific incompatibility among Populus hybrids in sections Aigeiros Duby and Tacamahaca Spach." Forestry Chronicle 87, no. 06 (December 2011): 790–96. http://dx.doi.org/10.5558/tfc2011-096.

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In our previous Populus breeding, compatible crosses between P. maximowiczii A. Henry and P. deltoides Bartr. ex Marsh corroborated the potential of interspecific hybrids, despite low seed set. Our current objective was to test the range of incompatibility among intraspecific and interspecific crosses using parental germplasm from the sections Aigeiros Duby (P. deltoides and P. nigra L.) and Tacamahaca Spach (P. maximowiczii). We determined the success rate of crosses, along with seed production and seedling viability. The success of crosses ranged from complete incompatibility to complete compatibility, with 29% to 85% of the transplanted germinants developing into healthy seedlings.
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15

Ke, Chen, Jia Xiuqing, Ren Peng, and Liu Jianqing. "Genetic relationships of poplar species in section Tacamahaca based on cpDNA and ISSR." Scientific Research and Essays 6, no. 19 (September 30, 2011): 4048–54. http://dx.doi.org/10.5897/sre11.289.

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16

Gom, Lori A., and Stewart B. Rood. "Patterns of clonal occurrence in a mature cottonwood grove along the Oldman River, Alberta." Canadian Journal of Botany 77, no. 8 (November 21, 1999): 1095–105. http://dx.doi.org/10.1139/b99-152.

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The conservation of the remaining riparian woodlands of western North America will benefit from a better understanding of cottonwood (poplar) regeneration. Following our discrimination of the 67 cottonwood clones present in an island population of 391 trunks, the present investigation characterized the grove's clonal architecture in terms of species, sex, spatial patterns, and beaver impacts. Large clones containing up to 53 trunks occurred near the river channel in areas prone to flooding, scouring, deposition, and beaver damage. Populus section Tacamahaca Spach. species Populus angustifolia James and Populus balsamifera L. produced larger (mean diameter = 9.2 m) clones with more ramets (mean = 6.7) than the section Aigeiros Duby species Populus deltoides Bartr. (7.3 m diameter, 2.7 ramets). The increased clonal nature of the Tacamahaca species is probably adaptive along steeper gradient streams in foothill regions where increased physical disturbance encourages clonal sprouting. Conversely, P. deltoides occurs along more gradually sloped reaches with finer substrates and smoother stage patterns that would favor seedling recruitment. The grove's clonal structure accounted for the female-biased sex ratio among trunks (204 females : 116 males) since the sex ratio was even among genets (49 females : 51 males). Clonality has contributed substantially to regeneration and grove composition, favoring certain genotypes and influencing woodland structural diversity and spatial distributions. Clonal characteristics differ across Alberta's cottonwood species and would influence the distribution of these native trees.Key words: asexual reproduction, beavers, clonality, cottonwoods, Populus, sex.
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17

Greenaway, W., S. English, and F. R. Whatley. "Phenolic Composition of Bud Exudates of Populus deltoides." Zeitschrift für Naturforschung C 45, no. 6 (June 1, 1990): 587–93. http://dx.doi.org/10.1515/znc-1990-0604.

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Abstract Bud exudate of Populus deltoides clones originating from six central and eastern American states was examined by gas chromatography/mass spectrometry and the components were identified. The principal components of the bud exudate were the flavone galangin, the flavanone pinocembrin and the flavanonol pinobanksin, together with the related compounds pinocembrin chalcone, pinobanksin methyl ether and pinobanksin-3-acetate. The bud exudate composition was very different from that seen in a North American poplar of the section Tacamahaca, P. balsamifera. The bud exudates from all P. deltoides specimens were similar excepting that from Vermont.
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18

Chen, Ke, Youhong Peng, Yuhua Wang, Helena Korpelainen, and Chunyang Li. "Genetic relationships among poplar species in section Tacamahaca (Populus L.) from western Sichuan, China." Plant Science 172, no. 2 (February 2007): 196–203. http://dx.doi.org/10.1016/j.plantsci.2006.08.009.

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19

Zhu, Jialei, Ju Tian, Jun Wang, and Shuijing Nie. "Variation of Traits on Seeds and Germination Derived from the Hybridization between the Sections Tacamahaca and Aigeiros of the Genus Populus." Forests 9, no. 9 (August 27, 2018): 516. http://dx.doi.org/10.3390/f9090516.

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Poplar is an important research organism, and species in sections Tacamahaca and Aigeiros, have advantages in terms of stress resistance, ease of propagation, and fast growth. Poplar species are widely distributed and well-adapted in the world, presenting a large potential for genetic improvement. Hybridization between different species allows us to generate offspring with a unique combinations of traits. This approach has a huge potential for breeding new poplar varieties that could aid in controlling desertification in the arid and semi-arid zones of the “Three-North” in China. In this study, we carried out a cross test scheme with nine female and thirteen male poplar trees. A total of 105,401 seeds were collected from 117 crosses. Flowering phenology and seed maturation differences of the hybrid progeny were monitored in greenhouses. For male trees, Populus deltoides had the longest flowering time. For female trees, Populus pseudo-simonii showed the longest seed maturity time. The number of carpals and ovules were not the same in different females. Meanwhile, three carpals were found in P. pseudo-simonii. A highly significant positive correlation was found between the seed size and the Thousand Kernel Weight, as well as the seedling cotyledon length. During seed germination, non-radicle and non-hypocotyl seedlings were observed. We also observed a number of cotyledon variants, including single and fused cotyledons, two cotyledons with one cotyledon cracking into two parts, three cotyledons, as well as four cotyledons. These results lay a favorable foundation for combining the research between the sections Tacamahaca and Aigeiros in future work.
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20

Proshkin, Boris V., and Andrey V. Klimov. "Systematic position of Populus ciliata Wall. ex Royle on the study of shoot morphology and petiolar anatomy." SOCIALNO-ECOLOGICHESKIE TECHNOLOGII 10, no. 1 (2020): 9–23. http://dx.doi.org/10.31862/2500-2961-2020-10-1-9-23.

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Анотація:
Populus ciliate – ciliated poplar is distributed in the Himalayas at altitudes from 1300 to 3400 m above sea level, along river banks and wet slopes. The systematic position of the taxon remains unclear, although in most modern works it is attributed to the Tacamahaca section. The purpose of this study is to study the morphological features of crown shoots and the anatomical structure of petioles of Populus ciliata leaves to clarify its systematic position. Studies of the morphology of P. ciliata showed that it did not have specialized shortened shoots marking a section of balsamic poplars – diskoblasts. The most important signs of petiolar anatomy allowing the identification of poplar taxa at the section level are: the shape of the petiole cross section, the contours of its adaxial and abaxial sides, the shape of the rings of closed collateral bundles, the shape of the vascular system. A comparison of the obtained sections of P. ciliata with representatives of the Tacamahaca section indicates that the plants studied do not belong to balsamic poplars, since they differ in the absence of a groove pronounced on the adaxial side. The latter in the form of a small recess in the slice is fixed only at the place of its transition into the leaf blade. The contours of the abaxial and adaxial sides are round, the shape of the vascular system of the petiole is not highly arched like that of balsamic poplars, but linear, formed by elliptical rings of closed collateral bundles.
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21

Mottet, Marie-Josée, Gilles Vallée, and Guy Bussières. "Test précoce pour l'évaluation de la sensibilité de peupliers hybrides au chancre septorien." Forestry Chronicle 67, no. 4 (April 1, 1991): 411–16. http://dx.doi.org/10.5558/tfc67411-4.

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Анотація:
Septoria musiva, a fungal pathogen that causes cankers and leaf spots, is found in hybrid poplar plantations (Populus spp.) in southern Québec. A high incidence of severe cankers is observed on susceptible poplars. To accelerate the evaluation for resistance to Septoria canker, sprouts were inoculated with S. musiva twice in the nursery. From the 725 clones tested, 100 showed a low degree of susceptibility. Among these, 45 belong to the Ageiros section, 13 to the Tacamahaca section and 42 are hybrids between the two sections. The four isolates used in this test demonstrate variations in aggressiveness. Key words: Septoria musiva, Septoria canker, screening for resistance, hybrid poplars.
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22

Keca, Nenad. "Diseases in poplar plantations." Bulletin of the Faculty of Forestry, no. 97 (2008): 7–31. http://dx.doi.org/10.2298/gsf0897007k.

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Анотація:
Production of poplar plantation is in great part in correlation with its health condition. Big areas under the trees of the same age and almost identical (sort) or identical (clones) genetical characteristics are ideal environment for occurrence and development of different diseases. They could easy reach epyphitotic intensity, in such conditions and start to endanger wood mass production and cause big financial loss. Aim of paper was to present the most important diseases worldwide, which are reported on poplar species of sections: Leuce, Aigeiros and Tacamahaca. Beside the most important diseases in paper are presented fungi which were found during many years of study of natural stands and plantations of poplars in Serbia.
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23

Zhang, Yan, Beibei Wang, Liqin Guo, Wenting Xu, Zewei Wang, Bailian Li, and Jinfeng Zhang. "Factors influencing direct shoot regeneration from leaves, petioles, and plantlet roots of triploid hybrid Populus sect. Tacamahaca." Journal of Forestry Research 29, no. 6 (December 16, 2017): 1533–45. http://dx.doi.org/10.1007/s11676-017-0559-4.

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24

Rood, Stewart B., Lori A. Goater, John M. Mahoney, Cheryl M. Pearce, and Derald G. Smith. "Floods, fire, and ice: disturbance ecology of riparian cottonwoodsThe review is one of a selection of papers published in the Special Issue on Poplar Research in Canada." Canadian Journal of Botany 85, no. 11 (November 2007): 1019–32. http://dx.doi.org/10.1139/b07-073.

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Анотація:
Cottonwoods are poplar trees that are well adapted to dynamic riparian, or streamside, zones throughout the Northern Hemisphere. Here we assess the influences of three prominent physical disturbances, floods, fire, and ice, on cottonwood population ecology. We emphasize cottonwoods along rivers from the “Crown of the Continent”, the central Rocky Mountain zone around the Canada – United States border, where five Populus species overlap and four hybridize. Moderate to major floods scour banks and deposit bars, creating barren and moist colonization sites that are essential for cottonwood seedling recruitment. Floods also scarify shallow roots, thus promoting clonal suckering, especially for the section Tacamahaca species: narrowleaf cottonwood ( Populus angustifolia James), balsam poplar ( Populus balsamifera L.), and black cottonwood ( Populus trichocarpa Torr. & A. Gray). Fire would naturally be less frequent in some riparian zones because of the moist conditions and firebreaks provided by the streams, but with human use, floodplain forest fires have probably increased. Following fire, regrowth through clonal root and shoot suckers can be prolific for the Tacamahaca species, but is limited for the section Aigeiros , prairie cottonwood ( Populus deltoides Bartr.). River ice, and especially ice drives that accompany winter or spring break-up, provide powerful riparian disturbances that have often been neglected. Ice drives generate barren sites for seedling colonization, shear shoots, and scarify roots promoting shoot and root suckering, and sever branches, enabling dispersive clonal branch propagation. Following studies along many regional rivers, we conclude that: (i) riparian cottonwoods are tolerant of, and dependent upon, occasional physical disturbance for population rejuvenation; (ii) differing disturbance responses contribute to niche differentiation across the Populus species; (iii) different disturbances enable varied spatial and temporal patterns of cottonwood establishment, including fringe, general, and patch recruitment; and (iv) natural disturbance regimes probably favor native cottonwoods and disfavor some invasive, woody plants. River damming and flow regulation often attempt to attenuate flood and ice disturbance, a management objective that may hinder the perpetuation of native floodplain forests. We recommend that river resource managers seek to allow flood and ice disturbance, and additionally, fire may provide a managed disturbance that could rejuvenate overmature cottonwood groves along some regulated rivers.
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25

Rajora, Om P., and Louis Zsuffa. "Allozyme divergence and evolutionary relationships among Populus deltoides, P. nigra, and P. maximowiczii." Genome 33, no. 1 (February 1, 1990): 44–49. http://dx.doi.org/10.1139/g90-008.

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Анотація:
Horizontal starch gel electrophoresis of enzymes was used to study genetic divergence among Populus deltoides Marsh. (section Aigeiros Duby, Salicaceae), P. nigra L. (section Aigeiros), and P. maximowiczii Henry (section Tacamahaca Spach.) at 37 to 40 allozyme loci coding for 12 enzyme systems in root tips. These three Populus species were genetically distinct from each other. Populus deltoides, P. nigra, and P. maximowiczii had mutually exclusive alleles at two loci, and each of these species had unique alleles at many loci. Certain allozyme loci were detected only in one or two of these species. Frequency distributions of allozyme loci were bimodal with respect to genetic identity for comparisons between any two species. The mean genetic distance was 0.36 ± 0.10 between P. deltoides and P. nigra, 0.39 ± 0.09 between P. deltoides and P. maximowiczii, and 0.34 ± 0.10 between P. nigra and P. maximowiczii. The enzyme electrophoretic evidence indicated a monophyletic origin of the three Populus species.Key words: poplars, genetic identity and divergence, allozymes, molecular evolution, phylogenetics.
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26

Rood, Stewart B., and Mary Louise Polzin. "Big old cottonwoods." Canadian Journal of Botany 81, no. 7 (July 1, 2003): 764–67. http://dx.doi.org/10.1139/b03-065.

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Анотація:
In studying riparian woodlands along streams across western North America, we observed a grove of exceptionally large and old black cottonwoods, Populus trichocarpa Torr. & A. Gray, along the Elk River in southeastern British Columbia. Situated in a floodplain forest dominated by western red cedar, Thuja plicata Donn ex D. Don, the cottonwoods were up to 2.2 m in diameter, and although heart rot prevented precise aging, increment cores indicated ages of up to 400 years. This demonstrated the potential for substantial longevity of section Tacamahaca cottonwoods (including Populus angustifolia James and Populus balsamifera L.) compared with section Aigeiros species (Populus deltoides Bartr. and Populus fremontii Wats.), which are shorter lived (about 150 year maximum). Very old cottonwoods make distinctive contributions to habitat structure of riparian woodlands and reveal stable floodplain locations that have not been eroded by the river channel for the duration of the trees' lives.Key words: aging, poplars, riparian, trees.
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27

Aliboni, Andrea. "Propolis from Northern California and Oregon: Chemical Composition, Botanical Origin, and Content of Allergens." Zeitschrift für Naturforschung C 69, no. 1-2 (February 1, 2014): 10–20. http://dx.doi.org/10.5560/znc.2013-0114.

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Анотація:
Propolis is a beehive product that bees manufacture by mixing their own wax with vegetable resins collected from different species of trees and bushes. The chemical composition of propolis is very variable because it depends on the flora locally available, and specimens from different geographical and climatic areas display unique properties. In this paper, the results of the chemical characterization of some propolis specimens collected in northern California and in Oregon are presented. Their chemical compositions show that all specimens contain resins from poplars of the Tacamahaca section (balsam poplars) - characteristic of the western part of the North American continent. Nevertheless, some of the specimens are of mixed origin because they also contain resins from poplars of the Aigeiros section (cottonwoods) - also present in this part of the world. Propolis causes allergies in sensitive human individuals, which are due to the presence of certain esters. The contents of known propolis allergenic esters - phenylethyl caffeate, 1,1-dimethylallyl caffeate, benzyl cinnamate, and benzyl salicylate - have been investigated in these specimens and found to depend on the botanical origin.
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28

Du, Kang, Qiang Han, Ying Zhang, and Xiangyang Kang. "Differential Expression of Genes Related to the Formation of Giant Leaves in Triploid Poplar." Forests 10, no. 10 (October 19, 2019): 920. http://dx.doi.org/10.3390/f10100920.

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Анотація:
Plant polyploids tend to have large leaves, but their formation mechanism has not yet been well explained. Therefore, daily transcriptomic differences between triploids and diploids from a synthetic Populus sect. Tacamahaca three times a day (i.e., 04:00, 09:00, and 21:00) were investigated using high-throughput RNA-seq analysis. In this study, we identified several transcription factors associated with giant leaves. The combined effects included the high expression of several transcription factors (WRKY, MYB, etc.) and hormone-related genes (e.g., activates auxin, cytokine, and brassinosteroid synthesis-related genes) that accelerate the synthesis and accumulation of endogenous hormones. High levels of growth hormones were maintained by reducing the genes’ expression of hormone metabolism and degradation. The coordination of hormones accumulated sufficient materials and energy for leaf growth and development. Thereby, cell division and growth were accelerated which enhanced the photosynthesis of leaves, and the increased accumulation of photosynthetic products led to giant triploid leaves. This study lays the foundation for revealing the molecular mechanisms in the formation of giant leaves in polyploids.
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29

Greenaway, W., S. English, and F. R. Whatley. "Relationships of Populus × acuminata and Populus × generosa with their parental species examined by gas chromatography – mass spectrometry of bud exudates." Canadian Journal of Botany 70, no. 1 (January 1, 1992): 212–21. http://dx.doi.org/10.1139/b92-029.

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Анотація:
Analysis by gas chromatography – mass spectrometry of bud exudates of Populus deltoides and Populus trichocarpa showed that they each contained a number of different compounds. Exudates of P. trichocarpa contained dihydrochalcones and sesquiterpenols, which were absent from the exudate of P. deltoides, but lacked the flavones, flavanones, and flavanonols present in the exudate of P. deltoides. Exudates of their hybrid, P. × generosa (P. × interamericana), contained compounds typical of both parent plants. Bud exudates of Populus angustifolia and Populus sargentii were qualitatively similar in their flavonoid composition but the exudate of P. angustifolia contained in addition caffeate esters, which were absent from P. sargentii. The exudate from the hybrid P. × acuminata was intermediate. Bud exudates of P. angustifolia and P. × acuminata were more like those of P. deltoides and P. sargentii (section Aigeiros) than they were to those of P. trichocarpa (section Tacamahaca). It is therefore suggested that P. angustifolia and P. × acuminata might be more correctly classified together with P. sargentii and P. deltoides within the section Aigeiros. Key words: Populus, bud exudate, chemotaxonomy, gas chromatography – mass spectrometry.
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30

Weisgerber, Horst. "Poplar breeding for the purpose of biomass production in short rotation periods in Germany: Problems and first findings." Forestry Chronicle 69, no. 6 (December 1, 1993): 727–29. http://dx.doi.org/10.5558/tfc69727-6.

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Анотація:
Investigations so far on the suitability of poplars for biomass production in short rotation periods in Germany were conducted almost exclusively with clones conceived for conventional cultivation. To introduce improved plant material, a special breeding program was implemented in Hann. Münden. It takes into consideration the most important criteria of suitability for the new form of land utilization. A report is given on findings so far from the realization of this program. Comprehensive basic plant material is available for European, North American and East Asian species from the sections Aigeiros, Leuce and Tacamahaca. Interspecific crossings are being carried out mainly in order to make the best possible use of combination and heterosis effects. A period of at least 20 years is necessary to develop new cultivars with high yield performance and yield stability. First results are presented on hybrids of species which are site-tolerant, resistant and particularly fast-growing at the juvenile phase. Plans to produce multiclonal varieties, each with 5 to 10 suitable clones with the same growing rhythm are in place. Special cultivation recommendations advocate clonal mixtures for each of the most important site units and for different rotation periods of from 2 to 5, 6 to 10 and more than 10 years. Key words: poplar, breeding, biomass, short rotation
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31

Pinon, Jean, Pascal Frey, and Claude Husson. "Wettability of Poplar Leaves Influences Dew Formation and Infection by Melampsora larici-populina." Plant Disease 90, no. 2 (February 2006): 177–84. http://dx.doi.org/10.1094/pd-90-0177.

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Анотація:
The wettability of leaves of 60 poplar (Populus spp.) clones from sections Aigeiros (black) and Tacamahaca (balsam) and their hybrids was assessed by measuring the contact angle of calibrated water droplets on their abaxial leaf surface. The frequency and duration of dew on these clones were recorded in two nurseries. Black poplar leaves had the highest wettability, with relatively flat-shaped water droplets and a short drying time, in both the laboratory and nursery. Conversely, round-shaped water droplets on balsam poplars dried more slowly in the laboratory. In the nursery, dew was more frequent and persisted longer. First-generation intersectional hybrids behaved like balsam poplars, but successive backcrosses with black poplar (P. deltoides) resulted in clones with leaves that were more wettable and possessed less frequent and persistent dew. Infection by Melampsora larici-populina on two hybrid clones (‘Robusta’ and ‘Beaupré’), assessed by the number of uredinia in the laboratory, was dependent on the duration of leaf moisture. Maximum infection occurred when water was present on the leaves for 12 h. Leaf wettability should be considered as an additional trait when breeding poplar for durable resistance to M. larici-populina, as this characteristic is likely to be a useful defense against all pathotypes of the pathogen.
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32

Albornoz, Marta V., Mauricio Lolas, Jaime A. Verdugo, and Claudio C. Ramírez. "Identification of Virulences of the Rust Fungus Melampsora larici-populina Occurring in Chile." Plant Disease 102, no. 11 (November 2018): 2201–4. http://dx.doi.org/10.1094/pdis-01-18-0033-re.

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Анотація:
Melampsora larici-populina Kleb. is a Eurasian species that causes leaf rust of many species of Populus from sections Tacamahaca and Aigeiros. This rust has been inadvertently introduced to many parts around the world affecting poplar species that grow naturally, which may be susceptible to this fungus. In Chile, early European settlers introduced poplars; rust, attributed to M. larici-populina, has been reported in these trees since 1918. However, a modern confirmation has been lacking, and pathogenic variation of the Chilean population of M. larici-populina has not been investigated. Using a morphological analysis of urediniospores and sequencing of internal transcribed spacer (ITS) regions, we confirmed the presence of M. larici-populina in Chile. ITS regions exhibited 100% homology with M. larici-populina. Scanning electron microscopy showed that spores were 26 to 47 µm in length, 13 to 16 µm in width, and echinulate except for apices, which are smooth, characteristics described for this species of rust. The variability of M. larici-populina is characterized by the presence of pathotypes, which allows the fungus to infect despite the resistance of certain poplar hybrids. We concluded that the identified spores belong to M. larici-populina, with virulences 1, 2, 3, 4, 5, and 6. These results describe variation in virulence of M. larici-populina, which suggests the presence of a sexual stage in Chile.
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33

Vysotska, N. "Сучасний стан і перспективи збереження генетичних ресурсів тополі в Україні". Наукові праці Лісівничої академії наук України, № 15 (30 листопада 2017): 38–44. http://dx.doi.org/10.15421/411705.

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Анотація:
Узагальнено інформацію про наявні площі природних і штучних деревостанів, розподіл за категоріями лісів, а також про видове різноманіття представлених в Україні тополь за результатами аналізу бази даних ВО "Укрдержліспроект". Встановлено сучасний стан лісових генетичних ресурсів тополі та пріоритети їхнього збереження і використання. З’ясовано, що у лісовому фонді рівнинної частини України представлено 7 видів тополь, які включено до секцій Aigeiros, Populus, Tacamahaca, зокрема: P. nigra, P. deltoides, P. alba, P. balsamifera, P. laurifolia, P. simonii, P. tremula, а також три культивари: P. nigra var. Pyramidalis, P. alba var. Bolleana і P. х canescens. Загальна площа тополевих лісів сягає 29071,1 га, зокрема природного походження – 15522,7 га. Визначено такі пріоритети зі збереження та сталого використання генетичних ресурсів тополі в Україні: поширення інформації про розповсюдження та використання, біологію та генетичну мінливість видів і популяцій тополі в Україні; розробка та реалізація стратегії та відповідної нормативно-правової бази зі збереження, відтворення та використання генофонду Populus sp.; відбір та паспортизація нових об'єктів, зокрема із застосуванням різних методів геномної та генної селекції, а також ДНК-маркування; дослідження міжвидової та внутрішньовидової мінливості тополь в умовах кліматичних змін та визначення значущості тополь у виконанні екосистемних послуг; укріплення раціонального використання ресурсів тополь, розвитку та управління ними. Для ефективного культивування тополі в Україні необхідно виконати такі ключові програмні та наукові заходи, як пошук міжнародних дослідницьких програм для розроблення інноваційного застосування тополь і створення нових клонів з підвищеною стійкістю проти посухи, засолення ґрунту та шкідників і хвороб.
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34

Kim, Gihwan, Ana P. Leite Montalvão, Birgit Kersten, Matthias Fladung, and Niels A. Müller. "The genetic basis of sex determination in Populus provides molecular markers across the genus and indicates convergent evolution." Silvae Genetica 70, no. 1 (January 1, 2021): 145–55. http://dx.doi.org/10.2478/sg-2021-0012.

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Анотація:
Abstract Many dioecious angiosperms are trees, which only flower after years of vegetative development and do not usually exhibit marked secondary sexual dimorphism. Nevertheless, if the genetic basis of sex determination is known, the sex of an individual can be determined using molecular markers. Here, we report that in the genus Populus sect. Populus an XY system of sex determination, which is found in P. tremula and P. tremuloides, likely re-evolved from a ZW system present in P. alba, P. adenopoda and P. qiongdaoensis. Strikingly, this new XY system is mechanistically identical to the older system found in several species of the Populus sections Tacamahaca, Aigeiros and Turanga demonstrating a remarkable example of convergent evolution. In both XY systems, male-specific inversely repeated sequences appear to silence the ARR17 gene, which functions as a sex switch, via small interfering RNAs and DNA methylation. In the ZW system, female-specific copies of ARR17 appear to regulate dioecy. With this detailed information on the genetic basis of sex determination it was possible to develop molecular markers that can be utilized to determine the sex in seedlings and non-flowering trees of different poplar species. We used the female-specific ARR17 gene to develop a sex marker for P. alba and P. adenopoda. For P. grandidentata, we employed the male-specific ARR17 inverted repeat. Finally, we summarize previously described markers for P. tremula, P. tremuloides, P. trichocarpa, P. deltoides and P. nigra. These markers can be useful for poplar ecologists, geneticists and breeders.
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35

Rytter, Lars, and Reimo Lutter. "Early growth of different tree species on agricultural land along a latitudinal transect in Sweden." Forestry: An International Journal of Forest Research 93, no. 3 (December 2, 2019): 376–88. http://dx.doi.org/10.1093/forestry/cpz064.

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Анотація:
Abstract Fast-growing tree species will be an important tool in the future production of renewables and in substituting non-renewable fossil energy sources. Sweden, like other countries around the Baltic Sea, has large areas of abandoned farmland usable for biomass production, but knowledge of growth performance of tree species candidates is insufficient. An experiment was initiated where six potentially high-producing tree species were compared. The best available plant material for each species was used on five sites over latitudes 56–64°N in Sweden. Results from the first 8–9 years are reported. Short rotation coppice willow (Salix schwerinii Wolf × S. viminalis L., clone ‘Tora’) had the fastest initial growth and production in southern Sweden. Hybrid aspen (Populus tremula L. × P. tremuloides Michx.) and poplar (Populus spp., section Tacamahaca), grown as short rotation forest, grew well over all sites and showed the highest productivity at the two northern sites. Hybrid larch (Larix ×eurolepis Henry) displayed a high potential at the two most southerly sites, whilst silver birch (Betula pendula Roth) was a medium-producing species at all sites. Norway spruce (Picea abies (L.) Karst.) started slowly, and Siberian larch (L. sukaczewii Dylis) produced poorly at the two northern sites in the initial stage. All tree species followed existing height development curves for the respective species on a high site quality level. Currently, well-growing clones of Populus spp. indicated that a wider selection of tree species can be used at high latitudes under climate change. The study showed a high growth potential for most species on former agricultural lands. However, measures to reduce climate and biological damage must be included in future efforts.
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36

Niemczyk, Marzena, Margalita Bachilava, Marek Wróbel, Marcin Jewiarz, Giorgi Kavtaradze, and Nani Goginashvili. "Productivity and Biomass Properties of Poplar Clones Managed in Short-Rotation Culture as a Potential Fuelwood Source in Georgia." Energies 14, no. 11 (May 23, 2021): 3016. http://dx.doi.org/10.3390/en14113016.

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Анотація:
Georgian forests are very valuable natural resources, but due to the lack of affordable alternatives to firewood, people are forced to use forest resources illegally and unsustainably. The aim of this study was to determine the productivity and biomass properties of four poplar clones from Aigeiros and Tacamahaca and one control clone, considering their wood and bark characteristics and their proportion in the stems. Short-rotation woody crops with these clones represent a potential source of commercial fuelwood production in Georgia as an alternative to natural forests. These tree characteristics were evaluated after three years of growth. The survival of the clones was generally high. No significant differences in biomass production (dry matter, DM) were found among the four clones tested (DM of approximately 4 Mg ha−1 yr−1), while the control clone achieved significantly lower values for DM. The biomass specific density was exceptionally high, at 481–588 kg m−3, which was a result of the high proportion of bark mass in the stem (23.3–37.7%), with a density almost twice that of wood. On the other hand, the tested clones had a very high ash content in the biomass (2.6–4.5%), which negatively affected their energy potential expressed as a lower heating value (17,642–17,849 J g−1). Our preliminary results indicated that both the quantity and quality of biomass are important factors to justify the investment in an intensive poplar culture. The four clones should be further considered for commercial biomass production and tested at different sites in Georgia to evaluate the genotype-by-environment interactions and identify the site conditions required to justify such an investment.
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37

Zheng, Wei, George Newcombe, Die Hu, Zhimin Cao, Zhongdong Yu, and Zijia Peng. "The First Record of a North American Poplar Leaf Rust Fungus, Melampsora medusae, in China." Forests 10, no. 2 (February 20, 2019): 182. http://dx.doi.org/10.3390/f10020182.

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Анотація:
A wide range of species and hybrids of black and balsam poplars or cottonwoods (Populus L., sections Aigeiros and Tacamahaca) grow naturally, or have been introduced to grow in plantations in China. Many species of Melampsora can cause poplar leaf rust in China, and their distributions and host specificities are not entirely known. This study was prompted by the new susceptibility of a previously resistant cultivar, cv. ‘Zhonghua hongye’ of Populus deltoides (section Aigeiros), as well as by the need to know more about the broader context of poplar leaf rust in China. Rust surveys from 2015 through 2018 in Shaanxi, Sichuan, Gansu, Henan, Shanxi, Qinghai, Beijing, and Inner Mongolia revealed some samples with urediniospores with the echinulation pattern of M. medusae. The morphological characteristics of urediniospores and teliospores from poplar species of the region were further examined with light and scanning electron microscopy. Phylogenetic analysis based on sequences of the rDNA ITS region (ITS1, 5.8S rRNA gene, and ITS2) and the nuclear large subunit rDNA (D1/D2) was used to further confirm morphology-based identification. Based on combined analyses, five of the fifteen fully characterized samples were identified as Melampsora medusae: one from Shaanxi and four from Sichuan. Two of the five were from Populus deltoides cv. ‘Zhonghua hongye’. Three others were identified on Populus szechuanica, P. simonii, and P. yunnanensis. Additional samples of M. medusae were collected in Shaanxi in 2017 and 2018, and from Henan in 2015 through 2018. Altogether these findings show that this introduced pathogen is widespread and persistent from year to year in China. This is the first report of this North American poplar leaf rust species, Melampsora medusae, in China. It has previously been reported outside North America in Argentina, Europe, Australia, New Zealand, Japan, and Russia.
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38

Рудник, А. М. "The study of compounds distilled with water vapor of Populus laurifolia Ledeb. leaves." Farmatsevtychnyi zhurnal, no. 3 (June 23, 2021): 56–62. http://dx.doi.org/10.32352/0367-3057.3.21.06.

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Анотація:
Poplar plants (Populus L.) are one of the promising species for inclusion in the State Pharmacopoeia of Ukraine. To date, extensive experience has been accumulated in the use of extracts from buds, leaves and bark of various types of poplars in folk and official medicine as effective anti-inflammatory, antipyretic, analgetic, antibacterial agents. According to literature data only buds are pharmacopoeial raw materials in some countries of the world. Poplar leaves are of interest as a new promising type of medicinal plant raw material, since they have a chemical composition close to the buds, moreover, they are much easier to harvest and the possible volume of raw materials procurement is much larger. The laurel-leaf poplar (Populus laurifolia Ledeb.) is assigned to the section of balsamic poplars (Tacamahaca). It is grown in forest culture, used for landscaping and creation of field-protective plantations in Ukraine. Continuing a comprehensive pharmacognostic study of raw materials of plants of the genus poplar, purpose of this work was to study composition and content of compounds distilled with water vapor of leaves of laurel-leaf poplar cultivated in Ukraine. Leaves for research were harvested in June 2019, from trees growing on the shores of the Murom reservoir in the village of Russkiye Tishki, Kharkiv region (50°09′30″N 36°29′10″E). The composition of compounds distilled in water vapor was investigated on Agilent Technologies 6890N (USA) chromatograph with a 5973N mass spectrometric detector. The total content of compounds distilled with water vapor was 2 126.1 mg/kg. 46 compounds were identified. Terpenoids were presented by 20 compounds with a total content 1 444 mg/kg, the remaining 26 compounds were aromatic substances (256.2 mg/kg) and compounds of various groups (216.8 mg/kg). The dominant compounds in content were β-eudesmol (776.4 mg/kg), γ-eudesmol (298 mg/kg), α-bisabolol (125.9 mg/kg), eugenol (70.9 mg/kg). The data obtained indicate the rich chemical composition of leaves of laurel-leaf poplar and are the basis for further in-depth study of this raw material for assessment the possibility of using it as a medicine.
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39

Ren, Jingshan, Xinyue Ji, Changhai Wang, Jianjun Hu, Giuseppe Nervo, and Jinhua Li. "Variation and Genetic Parameters of Leaf Morphological Traits of Eight Families from Populus simonii × P. nigra." Forests 11, no. 12 (December 11, 2020): 1319. http://dx.doi.org/10.3390/f11121319.

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Анотація:
Leaf morphology in Populus L. varies extensively among sections, species and clones under strong genetic control. P. nigra L. (section Aigeiros), with large and triangular leaves, is a commercial forest tree of economic importance for fast growth and high yield in Europe. P. simonii Carr. (section Tacamahaca) with small land rhomboid ovate leaves performs cold and dry resistance/tolerance in the semi-arid region of Northern China. Leaf morphological traits could be used as early indicators to improve the efficiency of selection. In order to investigate the genetic variation pattern of leaf morphology traits, estimate breeding values (combining ability), as well as evaluate crossing combinations of parents, 1872 intersectional progenies from eight families (P. simonii × P. nigra) and their parents were planted with cuttings for the clonal replicate field trial in Northern China. Four leaf size traits (area, perimeter, length, width) and roundness were measured with leaf samples from the 1-year-old clonal plantation. Significant differences regarding leaf traits were found between and among three female clones of P. simonii from Inner Mongolia, China and six male clones of P. nigra from Casale Monferrato, Italy. The genetic variation coefficient, heritability and genetic variance component of most traits in male parents were greater than these of female parents. Heritability estimates of male and female parents were above 0.56 and 0.17, respectively. Plentiful leaf variations with normal and continuous distributions exited in the hybrid progenies among and within families with the genetic variation coefficient and heritability above 28.49 and 0.24, respectively. Heritability estimates showed that leaf area was the most heritable trait, followed by leaf width. The breeding value ranking of parents allowed us to select the parental clones for new crosses and extend the mating design. Two male parental clones (N430 and N429) had greater breeding values (general combining ability, GCA) of leaf size traits than other clones. The special combining ability (SCA) of the crossing combination between P. simonii cl. ZL-3 and P. nigra cl. N430 was greater than that of others. Eight putatively superior genotypes, most combined with the female parental clone ZL-3, can be selected for future testing under near-commercial conditions. Significant genetic and phenotypic correlations were found between five leaf morphology traits with the coefficients above 0.9, except for leaf roundness. The results showed that leaf morphology traits were under strong genetic control and the parental clones with high GCA and SCA effects could be utilized in heterosis breeding, which will provide a starting point for devising a new selection strategy of parents and progenies.
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"Using petiole anatomy to identify hybrids between and species of Populus sections Aigeiros and Tacamahaca." Turczaninowia 22, no. 3 (September 23, 2019): 80–90. http://dx.doi.org/10.14258/turczaninowia.22.3.3.

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Pushkova, Elena N., George S. Krasnov, Valentina A. Lakunina, Roman O. Novakovskiy, Liubov V. Povkhova, Ekaterina M. Dvorianinova, Artemy D. Beniaminov, et al. "Genome and Transcriptome Sequencing of Populus × sibirica Identified Sex-Associated Allele-Specific Expression of the CLC Gene." Frontiers in Genetics 12 (August 11, 2021). http://dx.doi.org/10.3389/fgene.2021.676935.

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Transcriptome sequencing of leaves, catkin axes, and flowers from male and female trees of Populus × sibirica and genome sequencing of the same plants were performed for the first time. The availability of both genome and transcriptome sequencing data enabled the identification of allele-specific expression. Such an analysis was performed for genes from the sex-determining region (SDR). P. × sibirica is an intersectional hybrid between species from sections Aigeiros (Populus nigra) and Tacamahaca (Populus laurifolia, Populus suaveolens, or Populus × moskoviensis); therefore, a significant number of heterozygous polymorphisms were identified in the SDR that allowed us to distinguish between alleles. In the SDR, both allelic variants of the TCP (T-complex protein 1 subunit gamma), CLC (Chloride channel protein CLC-c), and MET1 (DNA-methyltransferase 1) genes were expressed in females, while in males, two allelic variants were expressed for TCP and MET1 but only one allelic variant prevailed for CLC. Targeted sequencing of TCP, CLC, and MET1 regions on a representative set of trees confirmed the sex-associated allele-specific expression of the CLC gene in generative and vegetative tissues of P. × sibirica. Our study brings new knowledge on sex-associated differences in Populus species.
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"Use of the anatomical and topographical structure of leaf petioles and. The location of stomata for identifing species. Of the Tacamahaca section of the genus Populus (Salicaceae)." Растительный мир Азиатской России 4 (2018). http://dx.doi.org/10.21782/rmar1995-2449-2018-4(30-36).

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Niemczyk, Marzena, and Barb R. Thomas. "Growth parameters and resistance to Sphaerulina musiva-induced canker are more important than wood density for increasing genetic gain from selection of Populus spp. hybrids for northern climates." Annals of Forest Science 77, no. 2 (March 19, 2020). http://dx.doi.org/10.1007/s13595-020-0931-y.

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Abstract Key message New genotypes of hybrid poplars from theAigeirosandTacamahacasections have great potential for increasing genetic gain from selection. The most promising traits are associated with productivity and resistance toSphaerulina musiva-induced canker while wood density can be selected for secondarily. A minimum age of 8 years is reliable to select fast-growing resistant clones in northern climates. Context Productivity, wood density, and disease resistance of hybrid poplar clones are important traits when selecting for cultivation at an industrial scale. Aims We studied 1978 hybrid poplar clones from 63 families, bred from poplars native (Populus balsamifera and Populus deltoides) and non-native to Canada from the Aigeiros and Tacamahaca sections, to improve economically important traits for plantations in northern Alberta. Methods Genetic parameters for diameter at breast height (DBH), height, resistance to Sphaerulina musiva-induced canker, and wood density were determined up to age 10. Results A mean annual increment of 16.5 m3 ha−1 year−1 was achieved at age 10 in the best-performing clones. The potential genetic gain for DBH, height, and canker resistance, 37%, 26%, and ~ 13%, respectively, was achieved when selecting the top 10% of the tested clones. The genetic effect for wood density was weak. The age-age genetic correlations identified age eight as a reliable selection age. Conclusion The new hybrid poplar clones tested exhibited great potential for tree improvement. The next phase of selection should test a reduced number of clones on different site types, identifying stable clones for productivity and resistance, while wood density can be selected for secondarily. In northern regions, a minimum age of 8 years is reliable to select fast-growing resistant clones for commercial deployment.
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Xu, Wenting, Liqin Guo, Yan Zhang, Jian Zhao, Zunzheng Wei, and Jinfeng Zhang. "An improved method for high-temperature induced embryo sac chromosome doubling in Populus simonii Carr. × P. nigra var. italica (Moench.) Kochne, an interspecific hybrid of Tacamahaca and Aigeiros poplars." Scientific Reports 9, no. 1 (January 24, 2019). http://dx.doi.org/10.1038/s41598-018-37297-w.

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