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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Morfofyziologické vlastnosti růstových modulů a jejich identifikace

Zemánek, Tomáš January 2003 (has links)
Angl. resumé
42

Porovnání struktury orgánů smrku ztepilého (Picea abies/L./ Karsten) (zejména kořenových systémů) za různých abiotických a biotických podmínek

Gebauer, Roman January 2005 (has links)
No description available.
43

Vybrané charakteristiky asimilačního aparátu smrku obecného :Picea abies /L./ Karsten /

Martinková, Milena January 1992 (has links)
No description available.
44

Larix decidua a introdukované druhy dřevin revíru Orlovy

Gregor, Zdeněk January 2012 (has links)
No description available.
45

Patterns of variation in Pacific silver fir (Abies amabilis [Dougl.] Forbes) on Vancouver Island

Davidson, Roberta H. January 1990 (has links)
This thesis describes patterns of variation in several cone, seed and seedling characteristics of Pacific silver fir (Abies amabilis [Doug.] Forbes) sampled from Vancouver Island, B.C. Cone collections kept separate by tree were made at eight locations during the fall of 1983 to provide material for the study. The inheritance patterns of 13 enzyme loci were determined from seed tissues of 87 trees, and seven loci were found to possess at least two allozyme variants. These loci conformed to the assumptions of Mendelian-type inheritance, although AAT-2 displayed marked segregation distortion. No linkage groups could be established at the sampling intensity available (20 seeds per tree). Significant levels of inbreeding, based on a multilocus estimate of outcrossing, were detected in five of seven populations and indirect evidence suggests related matings other than selfing may be occurring. Variation among populations in outcrossing rate was evident (0.725 < tm ≤ 1.0) and appears positively correlated with seed size (measured by 1000-seed weight). High levels of allozyme variation were found to exist within populations (95-98%) and estimates of the extent of population differentiation were shown to differ depending upon the particular analytic method employed. Maternal (extant) trees appeared more heterozygous than did viable embryos and populations sampled on southern Vancouver Island appeared more genetically diverse than did populations sampled on northern Vancouver Island. A sub-sample consisting of two populations, each with seven trees, from northern, mid and southern Vancouver Island provided material for a germination test and open-pollinated progeny study. Seed dormancy was not pronounced among populations. Large family differences in germination responses were detected, irrespective of pregermination treatment, suggesting a high degree of genetic control of germination in Pacific silver fir. Anomalous germination behavior in one population was attributed to sub-optimal stratification conditions and proliferation of mold. Improvement in production of seedlings of Pacific silver fir may be achieved by collecting and germinating seeds on a family-by-family basis. Germinants from the first count of the germination test provided open-pollinated progeny for measurement of growth variables. Seedlings were grown in a greenhouse alongside production Abies stock for 29 weeks. Population differences accounted for a considerable part of variance in cone and seed size. The effect of population on height of seedlings at eight weeks was significant but declined to virtually zero by the end of the test. Populations had negligible influence on growth rate of seedlings as well. Variation in growth rate among open-pollinated families was statistically significant but accounted for only 20% of the total variation. Significant population differences were detected in root weight of harvested seedlings. Family differences in this and other biomass variables were at most 20%, with the majority of variation in seedling growth traits residing within families. / Forestry, Faculty of / Graduate
46

Paprastosios eglės baltijos kilmių adaptacinių požymių geografinio kintamumo įvertinimas / Assessment of geographical variation among Baltic Norway spruce provenances in adaptive traits

Saldukaitis, Jonas 16 August 2007 (has links)
Tyrimų pagrindimas. Paprastoji eglė yra svarbi ūkinė rūšis Lietuvoje. Kilmių perkėlimas ir tolesnė selekcija gali ženkliai padidinti genetinę naudą gautiną iš p . eglės ūkinės paskirties medynų. Tuo tikslu, reikia informacijos apie genetinius skirtumus ir jų kitimo dėsningumus tarp p. eglės populiacijų perspektyviame introdukcijai Baltijos regione. Tyrimo tikslas- palyginti paprastosios eglės Baltijos regiono kilmių palikuonių adaptacinių, stiebo kokybės ir gyvybingumo požymių geografinio kintamumo dėsningumus bei kilmių perkėlimo ūkinę naudą bandomuosiuose želdiniuose. Objektas – 2001 m. įveisti paprastosios eglės Baltijos regiono kilmių palikuonių bandomieji želdiniai Kazlų Rūdos MMU (85 kilmės, po 50 kiekvienos kilmės medelių). Metodai – tyrimo metu buvo įvertintas medelių aukštis ir stiebo kokybė, nustatyta pumpurų sprogimo klasė, bei atlikta šių duomenų statistinė analizė. Rezultatai. Iš pietų į šiaurę perkeltų kilmių medeliai buvo aukštesni, geresnės stiebo kokybės ir vėliau pradėjo sezoninį augimą nei šiaurinių kilmių medeliai. Ypač mažu produktyvumu ir prasta stiebo kokybe pasižymėjo šiauriausios šiame bandyme pietų Suomijos kilmės, o šiaurinės Lenkijos kilmių medeliai produktyvumu lenkė vietinės kilmės medelius. Tai paaiškintina santykinai stipresniais šalnų pakenkimais, dėl ankstyvesnės šiauresnių kilmių sezoninio augimo pradžios ir mažesniu medeliu aukščiu dėl santykinai ankstesnės augimo pabaigos. Minėtų požymių geografinis kintamumas yra palaipsniui... [toliau žr. visą tekstą] / Background. Norway spruce is an imprint commercial forest tree specie sin Lithuanian. Provenance transfer and further breeding may markedly rise the benefit from commercial forests of Norway spruce,. For this purpose, there is a need of information on genetic variation and its geographical patters among Norway spruce provenances within the Baltic sea region of interest for introduction to Lithuania an don the benefit of the transfer itself. Objectives of the study are to compare the patterns of geographical variation among Baltic Norway spruce provenances in adaptive traits and to assess benefit of provenance transfer in the experimental plantation. The test. The study was carried out in an experimental plantation of Baltic Norway spruce provenances established in 2001 in Kazlu Ruda MMU (85 provenances of 50 trees each). Methods. Height, stem quality and stage of budburst in spring of the provenances were measured in the experimental plantation and statistical analysis methods were used to present the data. The results. The results showed that trees of the southern provenances were taller of better stem quality and later growth start in spring than trees of northern provenances. Trees of the most northern in this trial Finnish and Swedish provenances performed extremely poorly. Northern Polish provenances were more productive than the tree of the local origin. This result may be a consequence of spring frost damage of early flushing trees. The trees of northern... [to full text]
47

Studium vlivu fytohormonů a ektomykorhizních hub při maturaci a konverzi somatických embryí jehličnanů

Filippova, Mariia January 2015 (has links)
This thesis deals with the exploration of the influence of various phytohormones, primarily the influence of abscisic acid on the process of maturation and the influence of auxin and gibberellin on the process of germination of two types of conifers, Abies alba and Picea abies, often used as a material in the discovery of somatic embryogenesis. Each genotype prefers specific concentration ABA. 15 uM and 45 uM is the most effective for the cell lines Abies alba; 15 uM and 30 uM ABA for Picea abies. Auxin (IBA) and gibberellin (GA3) did not support the growth of roots of Abies alba. The interaction between fungal cultures Paxillus involutus and Amanita muscaria and between the embryos during the germination was studied as well. Fungal culture Paxillus involutus had very fast speed of growth on the germination medium. Fungal culture Amanita muscaria was growing very slowly. The effect of fungi on the germination has not been observed.
48

Dynamique des forêts de sapin de Cilicie au Liban et changements globaux : apports des analyses palynologiques et génétiques / Dynamics of Cilician fir forests in Lebanon and global changes : contribution of palynological and genetic analyses

Awad, Lara 22 September 2014 (has links)
Le Liban est un pays qui constitue un carrefour des civilisations. Depuis le temps des pharaons, ses ressources forestières ont été exploitées, notamment pour le commerce du bois. Le Liban, connu pour son cèdre, possède une autre espèce emblématique, le sapin de Cilicie, dont les forêts sont en majorité non protégées. Historiquement, le bois de sapin a été exploité durant le Nouvel Empire égyptien ancien pour la construction des temples et des navires. Il représentait ainsi un signe de pouvoir du pharaon, en formant notamment la barque d'Amon. De même, le sapin a été coupé pour la construction du temple de Jérusalem, ainsi que des instruments de musique et de guerre. La fragmentation des sapinières au Liban n'est pas ancienne mais cette faible divergence se traduit cependant par un dème Nord-Est englobant 11 populations et un dème Sud-Ouest englobant 4 populations qui semblent être le résultat de deux processus démographiques consécutifs ou simultanés durant l'histoire du sapin au Liban. Le premier est un phénomène de migration en altitude en réponse à des changements dans l'environnement ou le climat. La reconstruction de la dynamique passée du sapin au Liban a montré que le sapin a subi des fluctuations importantes dans sa taille, depuis le Tardiglaciaire, il y a 14,000 ans. Notamment, le sapin a connu des périodes d'absence du registre pollinique qui pourrait être liées à la fragmentation anthropique de l'habitat ou à des extinctions locales ou contraction de l'aire de répartition. De même, il a connu des périodes d'expansion notamment au cours des événements de sécheresse dans le climat, notamment à 4090 cal. BP, à 5010 cal. BP et de 7800 à 8090 cal. BP. La richesse en allèles privés dans le dème Nord-Est indique la présence de plusieurs micro-refuges glaciaires de basses et de hautes altitudes, ainsi que des zones de suture issues de la recolonisation. Dans le dème Sud-Ouest, une recolonisation postglaciaire en altitude à partir du seul micro-refuge glaciaire détecté est probable. Le deuxième phénomène est lié à une migration asymétrique des populations génétiquement diversifiées du centre du dème vers les populations marginales génétiquement peu diversifiées. Ce processus, qui semblait être le résultat de la faible taille des populations cibles, pourrait permettre de retarder l'extinction des populations marginales, localement menacées. La superformance de la migration sur la dérive génétique et la dispersion sur des longues distances de 15 à 20 km constituent les effets médiateurs de ces processus démographiques. L'empreinte de cette dynamique démographique est une réduction historique de la taille effective des populations sur le long terme avec un signal ancien plutôt que récent, et une diversité génétique et richesse allélique basses. Cette diversité génétique semble être façonnée par les effets anthropiques ainsi que par les changements dans l'environnement ou le climat. La conservation in situ et ex situ de ces sapinières est nécessaire pour préserver leur patrimoine historique et génétique. / The Lebanon is a country that constitutes a crossroads of civilizations. Back in the time of pharaohs, fir forests in Lebanon were exploited, particularly for the timber trade. Lebanon, known for its cedar, has another emblematic species, the Cilician fir, whose forests are in majority unprotected. Historically, the fir was used during the ancient Egyptian New Kingdom rule over Phoenicia for the construction of temples and ships. Notably, it represented a sign of power of the pharaoh, forming the sacred barque of Amun. Similarly, this tree was cut from Lebanon to build the temple of Jerusalem, as well as for making instruments of music and war. The fragmentation of the fir populations in Lebanon is not ancient but their low divergence, however, is marked by a Northeastern Ridge including 11 populations and a Southwestern Ridge including 4 populations that seem to be the result of two consecutive or simultaneous demographic processes during the history of fir in Lebanon. The first is a phenomenon of altitudinal migration in response to changes in the environment or climate. The reconstruction of the past dynamics of fir in Lebanon showed that it has undergone significant fluctuations in size, since the Late Glacial, 14,000 years ago. In particular, the tree has experienced periods of absence from the pollen record that could be related to anthropogenic habitat fragmentation or to local extinctions or contraction of the range of distribution. Similarly, there have been periods of expansion especially during periods of drought in the climate, at 4090 cal. BP, at 5010 cal. BP and between 7800 and 8090 cal. BP. The private allelic richness in the Northeastern Ridge indicated the presence of multiple glacial microrefugia of low and high elevations, as well as suture zones issues from recolonization. In the Southwestern Ridge, postglacial altitudinal recolonization from single microrefugial population is moslty probable. The second phenomenon is related to an asymmetric Northeast-Southwest migration from genetically diverse populations towards marginal and less genetically diverse populations. This process, which seems to be the result of the small size of the target populations, could help delay the extinction of marginal populations, locally threatened. The outperformance of migration over genetic drift and the dispersal over long distances of 15 to 20 km constitute the mediating effects of these demographic processes. The footprint of these population dynamics is a historic reduction in the effective population size on the long-term rather than on the short term, and weak genetic diversity and allelic richness. This genetic diversity seems to be shaped by anthropogenic effects as well as by changes in the environment or climate. In situ and ex situ conservation of fir populations in Lebanon is necessary to preserve their historical and genetic heritage.
49

Permeability in surface treated Norway spruce samples- Effect of wood properties / Fuktupptag i ytbehandlade granprover- Virkesegenskapers påverkan

Nilsson, Josefin January 2012 (has links)
In Norway spruce there's a large natural variation in durability but knowledge about what is causing this variation is missing. In this thesis the focus were put into investigating how the water uptake ability was affected by the influence of heartwood versus sapwood and wood properties such as density and annual ring width. Liquid water permeability was checked trough a modified version of EN 927-5 and samples were also investigated trough the Mycologg Method. The wide grown wood with a coating system (a priming oil and alkyd or acrylate paint) absorbed less water than the narrow grown wood in the permeability test. The Mycologg test showed a clear difference between wide and narrow grown wood. Further research is necessary to examine the impact of wood properties when it comes to water uptake.
50

Has modern Swedish forestry affected genetic diversity in Norway spruce stands?

Dahlberg, Helena January 2015 (has links)
Norway spruce is one of two dominating species in Swedish forestry and the most economically important tree species in Sweden. In order to preserve the ability to adapt to a changing environment and to keep populations healthy, genetic diversity has to be preserved. When choosing a small number of individuals from a natural stand to establish a seed orchard the population size decrease. With only a small number of genetically different individuals the risk of inbreeding increase. Furthermore if many clones of the same tree are used in one seed orchard there is also an increased risk selfing. The aim of this study was therefore to investigate whether genetic diversity in Norway spruce differs between age groups and if this can be attributed to forestry practices. All sampling was done from a single location in Västerbotten, Sweden and the different age groups were chosen to represent stands not affected by the modern forest industry to recently planted forests. The chosen age groups are young (12-18 years), intermediate (30-45 years), and old (above 85 years). From each age group 150 individuals were sampled. With genomic microsatellite markers each individual was genotyped at eight simple sequence repeat (SSR) loci. Results show an overall high genetic diversity with an average expected heterozygosity (He) at 0.842 and low genetic differentiation with an average fixation index among populations (FST) of 0.003. The genetic diversity of each age group was also high (He 0.832 to 0.843) and the inbreeding coefficient ranged from 0.061 in the old group to 0.078 in the intermediate group. The pairwise FST value was highest between the old group and the young group but the differentiation was only 0.005 (P=0.001). An analysis of molecular variance also showed that only 0.34% of the total genetic variance was explained by differences among age groups. This study found little evidence for a decrease in genetic diversity due to forestry practices and revealed high genetic diversity and low differentiation between the age groups, indicating a healthy population.

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