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Iskalni niz: "avtor" (Westergren Marjana) .

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71.
Genetic diversity of core vs. peripheral Norway spruce native populations at a local scale in Slovenia
Marjana Westergren, Gregor Božič, Hojka Kraigher, izvirni znanstveni članek

Povzetek: We investigated the levels of genetic diversity and population differentiation among core and peripheral populations of Norway spruce along an altitudinal gradient (from inversions to upper tree line) using isoenzymes (ISO) and nuclear simple-sequence repeats (SSR) markers on overlapping set of populations. Twenty-seven to seventy trees from 11 and 7 populations were genotyped with isoenzymes and SSRs, respectively. The results partially conform to the expectations of the central-peripheral hypothesis (CPH) and are consistent for both marker sets. Genetic differentiation among peripheral populations was low but significantly different from zero (FST-ISO = 0.013, FST-SSR = 0.009) and higher than that among core populations (FST-ISO = 0.007, FST-SSR = 0.005), conforming to central peripheral hypothesis. Contrastingly, levels of genetic diversity assessed by both richness and equitability measures did not significantly differ between peripheral and core populations (AR-ISO = 2.20 vs. 2.14, AR-SSR = 17.16 vs. 17.68, HE-ISO = 0.183 vs. 0.185, and HE-SSR = 0.935 vs. 0.935 for peripheral and core populations, respectively).
Ključne besede: central peripheral hypothesis, Picea abies (L.) Karst., genetic diversity, genetic differentiation, upper tree line, inversion
Objavljeno v DiRROS: 07.05.2018; Ogledov: 8139; Prenosov: 1811
.pdf Celotno besedilo (561,16 KB)
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72.
Identifikacija izvora gozdnega reprodukcijskega materiala bukve s pomočjo molekularnih metod
Marjana Westergren, Marko Bajc, Domen Finžgar, Gregor Božič, Hojka Kraigher, 2017, izvirni znanstveni članek

Povzetek: Od kakovosti in izvora gozdnega reprodukcijskega materiala (GRM) bodo odvisni genetska pestrost, struktura, preživetje in uspevanje sadik ter končno uspevanje in odpornost bodočega gozda. Zato mora Gozdarski inštitut Slovenije (GIS) na podlagi javnega pooblastila po Zakonu o gozdovih in zahtev zakonodaje o GRM preveriti njegov izvor pred izdajo glavnega spričevala ali na zahtevo inšpektorata kadarkoli v času trženja in uporabe. Uporaba molekularnih metod pripomore k vedenju o izvoru in genetski kakovosti GRM. GIS kontinuirano razvija znanje, infrastrukturo, gensko banko in molekularne baze podatkov za izvajanje opisanih testov. Zaradi suma o (načrtno) napačni navedbi izvora GRM, nabranega jeseni 2016 iz vsaj enega semenskega objekta, smo v predstavljeni študiji analizirali izvor in genetsko pestrost GRM iz štirih semenskih objektov bukve (Fagus sylvatica L.), v katerih je bilo seme nabrano v istem letu, ter drugih vzorcev iz Slovenske gozdne genske banke, skupaj petnajst. Za analize smo uporabili jedrne mikrosatelite, šestnajst lokusov, ki jih na GIS uporabljamo rutinsko. S tehničnega vidika so se izbrani markerji izkazali za primerne za identifikacijo posameznikov, oceno genetske pestrosti in identifikacijo domnevnega izvora. Zaradi možnosti mešanja vzorcev, pridobljenih s tal, in tehničnih potreb bomo v prihodnosti za potrebe rekonstrukcije genotipa semenskega drevesa analizirali vsaj dvanajst semen na drevo. Genetska pestrost manjših vzorcev je bila značilno manjša od tiste v velikih vzorcih. Opozarjamo, da je GRM nujno treba nabirati najmanj z v odobritvi semenskega objekta predpisanega števila dreves, da zagotovimo ustrezno veliko genetsko pestrost GRM, ki ga sadimo v gozdove. Metode razvrščanja posameznikov na podlagi Bayesove verjetnosti in filogenetska drevesa so pravilno določili izvor referenčnih vzorcev, medtem ko je bila resolucija analize glavnih komponent manjša. Vse metode, uporabljene za identifikacijo domnevnega izvora vzorcev semena, so nedvoumno pokazale, da vzorec TURs ni bil nabran v sestoju TUR, različen je tudi od preostalega analiziranega genofonda bukve v Sloveniji.
Ključne besede: Fagus sylvatica, gozdni reprodukcijski material, identifikacija izvora, genetska pestrost, mikrosateliti, analiza starševstva, Slovenija
Objavljeno v DiRROS: 03.09.2017; Ogledov: 4143; Prenosov: 771
.pdf Celotno besedilo (512,44 KB)

73.
Identification of types of ectomycorrhizae on seedlings in a beech provenance trial
Marjana Westergren, Tine Grebenc, Gregor Božič, Robert Brus, Hojka Kraigher, 2004, izvirni znanstveni članek

Povzetek: Root systems and types of ectomycorrhizae (ECM) were analysed on three 7-year-old beech seedlings (Fagus sylvatica L.) of three provenances (Val di Sella, Idrija, Nizbor) from an international beech provenance trial and on a naturally regenerated 5-year-old beech seedling from the same site (Kamenski vrh by Novo mesto). All short roots were mycorrhizal. In the sampled 20,302 root tips 49 % were non-turgescent and unidentifiable ECM. Twenty-two different types of ECM were identified, out of which 11 were successfully determined either to the species or genus level. All ECM were described by morphological and anatomical characteristics, basidiomycetes also by molecularmethods. ECM that was not successfully determined either to the species or genus level formed a new cluster in the Slovenian mycorrhizal molecular database. Species richness and percentage of vital ECM roots were highest for the provenance from Idrija (Slovenia). The results indicate that there might be differences between provenances regarding the abundance of ECM,which should be further studied.
Ključne besede: beech, provenance trial, ectomycorrhizae, types of ectomycorrhizae
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4516; Prenosov: 1939
.pdf Celotno besedilo (2,48 MB)

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Distribution of neutral nuclear genetic diversity of European beech in two managed stands and a secondary virgin forest reserve: a case study
Marjana Westergren, Gregor Božič, Hojka Kraigher, 2014, objavljeni povzetek znanstvenega prispevka na konferenci

Objavljeno v DiRROS: 12.07.2017; Ogledov: 2331; Prenosov: 935
.pdf Celotno besedilo (4,10 MB)
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Morphological variability of Fraxinus angustifolia Vahl in the north-western Balkans
Kristjan Jarni, Marjana Westergren, Hojka Kraigher, Robert Brus, 2011, izvirni znanstveni članek

Povzetek: Fraxinus angustifolia Vahl is a species native in the north-western Balkans, where it has a divided range. Most of its range is located in flood-prone riparian sites in the Pannonian plain but the species is also found on humid sites along some rivers in the Submediterranean region. We analysed morphologic variation within and between five populations (14 trees/population) located in the Subpannonian and Submediterranean region of Slovenia. Thirty two characters were assessed on ca. 80 leaves from each tree which were divided depending on exposure to sunlight (sun and shade leaves), and 8 traits on each fruit (ca. 50 fruits/ tree). A hierarchically designed experiment using analysis of variance confirmed the significant contribution of all the analysed hierarchical levels of variation to the total variation. The results show that the differences between the trees in a single population are the greatest factor of variability of leaves, followed by differences between populations and differences which are the result of variation in exposure to sunlight. Leaves in shade positions are typically larger than those in sunny positions, and they have broader and shorter-pointed leaflets; in this feature they are very similar to the leaves of F. excelsior. Stepwise discriminant analysis showed that the traits which refer to the leaflet number and length are the best differentiating traits between individual populations. The Submediterranean population Dragonja stands out with the smallest leaves and the population Lijak from the same region is the most similar to Dragonja for most morphological traits. In general, phenotypic differences between the Subpannonian and the Submediterranean populations of F. angustifolia are minor and indistinct. Based on the differences ascertained by the study, we can only confirm the presence of F. angustifolia subsp. oxycarpa (Bieb. ex Willd.) Franco et Rocha Alfonso in this part of its natural range.
Objavljeno v DiRROS: 12.07.2017; Ogledov: 2992; Prenosov: 1370
.pdf Celotno besedilo (772,86 KB)
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