scholarly journals Genetic differentiation of Quercus robur in the South-Ural

2019 ◽  
Vol 68 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Bernd Degen ◽  
Ruslan Yanbaev ◽  
Yulai Yanbaev

Abstract We studied the genetic composition of 200 pedunculate oak (Quercus robur) trees at nine nuclear microsatellite gene loci. We sampled nine locations in an area of 1100 km by 400 km in the South-Ural. The question was to analyse the genetic differentiation of the oaks at the south-east edge of the species distribution area. We observed relatively high values of genetic differentiation and fixation (delta=0.387, FST=0.0652, FST(Hedrick)=0.407) compared to values from the centre of the species distribution range. Bayesian clustering analysis revealed three genetic groups. Presence of all genetic groups was detected at all locations, but oak trees in the extreme east of the Ural Mountains were genetically most different. We hypothesise that genetic drift influenced the observed pattern.

Author(s):  
Katrin Burger ◽  
Markus Müller ◽  
Martin Rogge ◽  
Oliver Gailing

AbstractSlavonian oaks (Quercus robur subsp. slavonica (Gáyer) Mátyás) originating from Croatia have been cultivated in Germany mainly in the Münsterland region of North Rhine-Westphalia since the second half of the nineteenth century. Compared to indigenous pedunculate oak stands in Germany, they are characterised by their late bud burst, but also by their excellent bole shape and faster height growth. Previously, Slavonian pedunculate oaks (= late flushing oaks) were mainly studied at chloroplast (cp) DNA markers in order to determine their geographical origin. The origin of the material is probably the Sava lowland between Zagreb and Belgrade. In the present study, the aim was to genetically differentiate between indigenous Quercus robur and Slavonian oak stands using nuclear DNA markers. For this purpose, we used 20 nuclear Simple Sequence Repeats (nSSRs). A total of 37 pedunculate oak stands (mean: 18.6 samples per population with an age of 95 to 210 years) were examined, of which 21 were characterized as Slavonian late flushing oaks and three stands for which the Slavonian origin was not clear. Maternally inherited chloroplast markers were analysed earlier in all 37 stands to validate their geographic origin. We found that the stands of native pedunculate oaks and Slavonian pedunculate oaks are represented by two genetic clusters which are weakly differentiated. Slavonian oaks (Na = 9.85, Ar = 8.689, Ho = 0.490, He = 0.540) showed similar levels of genetic variation as native oak stands (Na = 7.850, Ar = 7.846, Ho = 0.484, He = 0.526). Differences in growth and phenology and low but consistent genetic differentiation between groups suggest that both taxa represent different ecotypes with specific local adaptations, which are perhaps separated by less overlapping flowering phenologies. The nuclear microsatellite markers in combination with the cpDNA markers are suitable to differentiate between Slavonian and local oak stands.


2021 ◽  
Vol 67 (No. 11) ◽  
pp. 522-532
Author(s):  
Artur Akhmetov ◽  
Ruslan Ianbaev ◽  
Svetlana Boronnikova ◽  
Yulai Yanbaev ◽  
Aygul Gabitova ◽  
...  

Norway maple (Acer platanoides L.) is a key species of broadleaved forests whose population genetics is poorly studied using modern genetic tools. We used ISSR analysis to explore genetic diversity and differentiation among 10 Russian populations on the eastern margin of the species range of distribution, and to compare the revealed patterns with the results of our population genetic studies of pedunculate oak (Quercus robur L.). In the first set comparatively high heterozygosity and allelic diversity were found (expected heterozygosity H<sub>E</sub> = 0.160 ± 0.033, number of alleles n<sub>a</sub> = 1.440 ± 0.080, effective number of alleles n<sub>e</sub> = 1.271 ± 0.062) in comparison with strongly fragmented and geographically isolated small maple stands of the second set (H<sub>E</sub> = 0.083 ± 0.011, n<sub>a</sub> = 1.281 ± 0.031, n<sub>e</sub> = 1.136 ± 0.019). A relatively high genetic differentiation among populations was detected (the proportion of the inter-population component of total genetic variation, G<sub>ST</sub> = 0.558 ± 0.038). In the Cis-Urals, local groups of populations that are confined to the northern, middle and southern parts of the Urals were identified. On the contrary, the current significant fragmentation of the pedunculate oak distribution area in the same study area did not lead to any noticeable genetic differentiation among the majority of populations, the values of the population genetic diversity were very similar in different parts of the Southern Urals.


2021 ◽  
Vol 13 (1(22)) ◽  
pp. 13-20
Author(s):  
Petru Cuza ◽  

Extreme weather events with high temperatures and strong sunlight have increased alarmingly in the last few decades, considerable affecting plant photosynthesis. In this study, the impact of thermal stress on photosystem II activity in the leaves of pedunculate oak trees (Quercus robur L.) of different ecological origin was assessed. Four days after the thermal shock application with a temperature of 50°C during 20, 40, 60 minutes, the processes of recovery on photosystem II activity in the leaves of the oak trees in the investigated provenances took place with different speed and fullness. The recovery of the functional state of photosystem II in the leaves of the trees showed that in the environmental conditions of the ,,Plaiul Fagului” reservation territory an advanced thermotolerance to the thermal stress action was specifi c for the origin from the north of the country (Edinet). The leaves of the trees of local and southern origin showed a low resistance to the thermal stress action. The advanced adaptation capacity, the high growth rate of the trees from the northern provenance suggest that the acorn harvested from the oaks of northern origin can be used for the works of extension of the afforestation areas in the central area of the Republic of Moldova.


Author(s):  
С.Н. Кружилин ◽  
Т.Ю. Баранова ◽  
А.А. Багдасарян

Государственный природный заказник "Горненский", расположенный в центральной части Ростовской области, являясь особо охраняемой природной территорией областного значения, имеет уникальные объекты, представленные искусственно созданными лесными насаждениями дуба черешчатого (Quercus robur L.). В современном лесном хозяйстве черноземной зоны дуб черешчатый продолжает занимать лидирующие позиции по хозяйственному значению. Большое внимание при выращивании леса уделяется продуктивности. Насаждения, устойчивые насаждение к болезням, вредителям и неблагоприятным природным явлениям, всегда являются продуктивными и имеют большой показатель запаса древесины на единицу площади. Усыхание дубрав в последние годы становится актуальной проблемой. Основными факторами этих процессов являются повреждения вредителями и инфекционными заболеваниями. Повышению устойчивости деревьев дуба черешчатого в насаждениях способствуют своевременные рубки ухода. Авторы провели анализ посадок дуба черешчатого, сформированных с участием основной сопутствующей породы – клена остролистного. Исследовано 2 варианта лесных культур дуба в условиях сухой дубравы (Д1), определены лесоводственно-таксационные показатели в разные возрастные периоды. Отмечается, что при отсутствии в них плановых рубок ухода в периоды с 25 до 40 и с 35 до 50 лет происходит падение бонитета с 1 до 2 класса. Наряду с этим отмечается суховершинность деревьев, что приводит к задернению поверхности почвы и, соответственно изменению условий произрастания. The Gornensky State NatureReserve,situated in the central part of the Rostov Region, isa protected natural area of regional significance. The reserve contains unique objects, represented by artificially created forest stands of pedunculate oak (Quercus robur L.). In the modern forestry of the Chernozem zone,pedunculate oak continues to take a leading position in terms of its economic value. Much attention is paid to productivity when growing forests. Plantings that are resistant to diseases, pests, and adverse natural phenomena are always productive and have a large stock of wood per unit area. The diebackof oak forests has become an urgent problem in recent years. The main factors of these processes are damage by pests and infectious diseases. Timely improvement felling of oak trees helps to increase the stability of the stands. The authors analyzed plantings of petiolate oak formed with the participation of the main accompanying species– Norwaymaple. Twovariants of forest oak plantationsin the conditions of a dry oak forest (D1) were studied, and forestry and taxation indicators were determined for different age periods. It is noted that in the absence of planned improvement felling in the periods from 25 to 40 and from 35 to 50 years, there is a drop in the yield class from 1 to 2. Along with this, the diebackof trees is noted, which results inthe grassing-downof the soil surface and, accordingly, changes in the growing conditions.


2020 ◽  
Vol 16 (5) ◽  
Author(s):  
Pekka Vakkari ◽  
Mari Rusanen ◽  
Juha Heikkinen ◽  
Tea Huotari ◽  
Katri Kärkkäinen

Abstract The genetic structure of populations at the edge of species distribution is important for species adaptation to environmental changes. Small populations may experience non-random mating and differentiation due to genetic drift but larger populations, too, may have low effective size, e.g., due to the within-population structure. We studied spatial population structure of pedunculate oak, Quercus robur, at the northern edge of the species’ global distribution, where oak populations are experiencing rapid climatic and anthropogenic changes. Using 12 microsatellite markers, we analyzed genetic differentiation of seven small to medium size populations (census sizes 57–305 reproducing trees) and four populations for within-population genetic structures. Genetic differentiation among seven populations was low (Fst = 0.07). We found a strong spatial genetic structure in each of the four populations. Spatial autocorrelation was significant in all populations and its intensity (Sp) was higher than those reported in more southern oak populations. Significant genetic patchiness was revealed by Bayesian structuring and a high amount of spatially aggregated full and half sibs was detected by sibship reconstruction. Meta-analysis of isoenzyme and SSR data extracted from the (GD)2 database suggested northwards decreasing trend in the expected heterozygosity and an effective number of alleles, thus supporting the central-marginal hypothesis in oak populations. We suggest that the fragmented distribution and location of Finnish pedunculate oak populations at the species’ northern margin facilitate the formation of within-population genetic structures. Information on the existence of spatial genetic structures can help conservation managers to design gene conservation activities and to avoid too strong family structures in the sampling of seeds and cuttings for afforestation and tree improvement purposes.


2021 ◽  
Vol 875 (1) ◽  
pp. 012049
Author(s):  
N N Kharchenko ◽  
V N Kalaev ◽  
V O Kornienko

Abstract The paper studies the mechanical resistance of old-age pedunculate oak trees which grow at the environmental boundary of the species distribution in the steppe. The trees of the studied species growing in the south of the East European Plain (Donetsk Ridge) can be about 200 years old and still be viable (good condition) and have a high mechanical resistance (critical mass (mcr)=105 kg, and flexural stiffness=9.8·107 N·m2) even under unfavourable environmental conditions. A strong dependence of the morphometric parameter of the ratio was established between the tree trunk diameter and its height on the parameters of the trunk bending stiffness, its critical mass, and the relative resistance to bending. The obtained results of statistical analysis can be used to monitor oak forests and scattered trees of Quercus robur L. in order to single out plants with low mechanical resistance with the help of the d/l parameter which serves as a morphometric marker of the tree resistance.


2005 ◽  
pp. 9-29 ◽  
Author(s):  
Dragan Karadzic ◽  
Tanja Milijasevic

The most frequent fungus species known as powdery mildews, causing the diseases of forest trees, were studied. Among forest woody species, oaks are especially susceptible to powdery mildew attack, and among them pedunculate oak (Quercus robur L) is highly endangered. This paper reports 49 species of powdery mildews. However, Microsphaera alphitoides has the greatest significance in forest economy, causing the decline of seedlings in nurseries and also aggravating the natural regeneration of pedunculate oak. This fungus, together with gypsy moth and honey fungus (Armillaria mellea) participates in the dying of old oak trees. Powdery mildews can be successfully controlled by fungicides, and sulphur fungicides Karatan and Rubigan are especially effective.


2021 ◽  
Vol 101 (4) ◽  
pp. 437-449
Author(s):  
I. V. Ermolaev ◽  
V. I. Ponomarev ◽  
A. A. Vasil’ev ◽  
M. S. Kumaeva

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