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  • Promising Leuce poplar clones in sandy ridges between the rivers Danube and Tisza in Hungary: a case study
    111-113
    Views:
    214

    An intensive integrated research and development work has been carried out on the improvement of Leuce poplars including primarily the native white poplar (Populus alba L.) and its natural hybrid grey poplar (Populus × canescens). More than 70 percent of the Leuce poplar stands can be found on calcareous sandy sites in the Danube–Tisza region, so they play a significant role in the poplar management of this part of the country. The most important task ahead of Hungarian poplar growers is to improve the quality of poplar stands and plantations based on selecting new clones and cultivars. The growth and yield of four promising Leuce poplar clones was evaluated on a marginal site in central Hungary. The clones ‘H 425-4’ (Populus alba L. × Populus alba L.), and ‘H 758’ (Populus alba L. Mosonmagyaróvár 124) seem to be suitable for wood production, while the ‘H 427-3’ (Populus alba L. × Populus alba L. cv. Bolleana) and ‘H 422-9’ (Populus alba L. × Populus grandidentata (Michx)) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.

  • Investigation of the decomposition and leaching dynamics of Salix, Populus and mixed leaves in the area of Lake Balaton and Kis-Balaton Wetland
    119-124
    Views:
    182

    In lakes and wetlands, leaf litter input from the coastal vegetation represents a major nutrient load and plays a basic structural and functional role in several ecosystems. In Hungary, at the banks of lakes and wetlands, Salix and Populus trees are the most common species. In an experiment in Lake Balaton and Kis-Balaton Wetland between 16 November 2017 to and 3 June 2018, the decomposition rates and leaching dynamics of Salix, Populus and mixed leaves (50% Salix and 50% Populus) were investigated. Total nitrogen and phosphorus content of biomass samples were measured at the beginning and end of the experiment for the leaching dynamics experiment. We found that litter mass losses (Salix, Populus and mixed leaves) were not significantly different between the two mesh size litterbags and between Lake Balaton and Kis-Balaton Wetland. Different amounts of the total nitrogen and phosphorus leaching from Salix, Populus and mixed leaves were detected. The total nitrogen contents of the plant samples were around 8-18% at the end of the investigated period. Slightly higher values were measured compared to phosphorous (27-29%).

  • Intensity of free radical processes in the leaves of arboreal plants under act of industrial dust borne extracts
    83-87
    Views:
    61

    The influence of industrial pollutants on the intensity of lipid peroxidation in the assimilatory organs of arboreal plant was investigated. The differential changes of the probed indexes are set depending on the species. Information is got can testify to participation of lipid peroxidation products in forming of reactions-answers of arboreal plants on influence of industrial dust borne extract with content of heavy metals. Determination of level and rates of accumulation of Zn, Ni, Pb and Cd, in the leaves of arboreal plants in the conditions of different 
    contamination level allowed to take species to two groups. To the first (phytoextraction potential exceeds a base-line level in 10 times) belong Populus bolleana Lauche, P. italica (Du Roi) Moench, Picea pungens Engelm and Sorbus aucuparia L. To the second (exceeds a base-line level from 5 to 10 times) belong Acer negundo L., Aesculus hippocastanum L., Betula pendula Roth and Tilia cordata Mill. The most substantial increase of peroxidation secondary product content (more than in 2.5 times) is peculiar for B. pendula, A. hippocastanum and P. pungens Engelm., that well conforms to the rates of heavy metals translocation, it has however species-specific character.

  • Microsatellite Diversity of Androgenic Black Poplar (Populus nigra)
    60-67
    Views:
    67

    Genetic variation of somatic clones (1 to 35) of black poplar (Populus nigra) developed from two anther-donor trees N-SL and N-309 was determined by five SSR primer pairs. Twenty SSR alleles were detected, the number of alleles per marker ranged from 1 to 6, with an average of 3.3 including WPMS-2 (5 alleles), WPMS-4 (6 alleles), WPMS-6 (2 alleles), WPMS-20 (6 alleles) and PTR-4 (1 allele) detected by ALF (automatic laser fluorometer). A
    dendrogram produced by SPSS11 based on the presence versus absence of SSR alleles discriminated the groups of somatic clones of N-SL from somatic clones of N-309. The polymorphic markers of WPMS-2 (5 alleles), WPMS-4 (6 alleles) and WPMS-20 (6 alleles) revealed clonal variation in 1 clone (37) out of the 6 from the N-309 tree, and three subgroups out of the 29 somatic clones from the N-SL tree (17 and 24), (2 and 14) and (10 and 15). The remaining 23 of the 29 N-SL somatic clones with uniform genetic similarity suggests a good degree of genetic stability in black poplar. Nevertheless, the new SSR-clones may provide useful new genetic resources for poplar breeding. 

  • Investigation of Salix alba and Populus tremula leaf litter decomposition in the area of Lake Balaton and Kis-Balaton Wetland
    159-162
    Views:
    156

    Plant litter decomposition in inland waters contributes significantly to nutrient load, particularly in still waters, such as shallow lakes and wetlands. The decomposition rates of Salix alba and Populus tremula leaf litter was examined in Lake Balaton and Kis-Balaton Wetland, using litter bag technique. Leaf litter was incubated in small (ᴓ=3 mm) and large (ᴓ=900 μm) mesh size bags for the assessment of the relative contribution of macroinvertebrates to leaf litter decomposition. Dry mass, exponential decay coefficient and chemical parameters of water (pH, conductivity, NH4 +, NO3 -, SO4 2-, PO4 3-, Cl-) were determined. Leaf mass loss showed negative exponential pattern during the 168 days of the decomposition period. Leaf litter mass loss generally did not differ between the small and large mesh sizes, suggesting that macroinvertebrates generally have a negligible role in leaf decomposition in the winter period.

  • A simplified growing model for mixed black locust (Robinia pseudoacacia L.) and poplar (Populus spp.) plantations in the Danube-Tisza Interfluve
    97-100
    Views:
    94

    This study presents a static model of mixed black locust (Robinia pseudoacacia L.) plantation stand structures for inventory stand structures between 10 and 40 years of age. Due to its local character, the model can be advantageous in planning tending operations, making structural factor predictions for the standing stock (main stand) after tending cuts, and preparing local wood production and silvicultural models. The model data presented in this paper show that poplars account for 55–62 % of the volume per hectare due to their faster growth rate in mixed black locust and poplar plantations. Maintaining the black locust part of the stand necessitates harvesting the poplars by the age of 10 at the latest.

  • Examination of the decomposition of willow (Salix sp.), poplar (Populus sp.), reed (Phragmites australis) and mixed leaf litter with litterbag technique
    111-115
    Views:
    75

    Leaf litter decomposition is one of the main ecological material cycle processes in waterfront areas. In this microcosm experiment, the rate of decomposition of the most frequently occurring dominant waterside plants were examined in the summer months of 2022 in a class “A” evaporation pan, using litterbag technique. The study provides information about the decomposition dynamics of willow (Salix sp.), poplar (Populus sp.), reed (Phragmites australis) and different leaf litter mixture combinations. Dry mass, exponential decay coefficient and the chemical parameters of the water (pH, conductivity, NH4+, PO43-, SO42-) were determined during the 84 days long experimental period. The weight loss curves showed negative exponential pattern in every case. On average, the different samples lost ~ 57% of their initial dry mass during the experimental period. The largest mass loss was measured in case of poplar (67.2%), while reed leaves had the smallest mass loss (47.25%). Based on the results, it cannot be proven, that mixed leaf litter accelerates the rate of decomposition.

  • DHAC-induced transgene overexpression in 35S-gshI GMO poplar (Populus × canescens)
    78-83
    Views:
    33

    Relative gene expression levels of transgene gshI (γ-glutamylcysteine synthetase cloned from E. coli) were analyzed by qRT-PCR in two transgenic poplar (Populus × canescens) clones (11ggs and 6lgl) and wild type (WT). An extremely high expression level of transgene gshI was observed in the 6lgl clone (13.5-fold) compared to 11ggs (1.0) samples, which level was doubled (1.8-fold) in the DHAC (5.6-dihydro-5'-azacytidine hydrochloride) treated (at 10-4 M for 7 days) 6lgl samples but not in the 11ggs clone (0.4-fold). Contrary to this result, relative copy number of transgene gshI in the 6lgl clone was found to be less 60% less (1.0) then in the 11ggs samples (1.6). Relative expression levels of proper poplar gene gsh1-poplar showed significantly higher responsiveness to DHAC treatment than transgene gshI with the highest expression level in the untransformed (WT) poplar
    clone (19.7-fold) compared to transformed 6lgl (8.7-fold) and 11ggs (2.5-fold) clones. For internal controls constitutively expressed housekeeping genes a-tubulin were applied. For data analysis, the 2−ΔΔCt method was used. DHAC applied in long-term cultures (27 days) at low concentrations (10-8 – 10-6 M) showed morphogenetic activity by initiating de novo root development of leaf discs.