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1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

LaCl3 induces genomic DNA instability and increases DNA methylation levels in wheat roots

100%
Lei X., Ma K., Zhang F.
Acta Biologica Cracoviensia. Series Botanica
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2021
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tom 63
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nr 1
2

Determinants of plant species richness in different wetland types along a hydrological gradient: implication for conservation

88%
Shi J., Ma K., Wang J., Zhang Y., Zhao J.
Polish Journal of Ecology
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2013
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tom 61
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nr 4
The loss of biodiversity caused by wetland degradation is a hot issue in ecology. It is known that hydrological degradation is the primary reason resulting in wetland degradation, but little is known about the relationship between plant species richness and environmental factors in different wetland types along a hydrological gradient. According to the gradient from high to low water level, wetland remnants in the Sanjiang Plain of northeast China were classified into three wetland types, which were permanently inundated marshes (PIM), seasonally inundated marshes (SIM) and wet meadows (WM) respectively. In this paper, we aimed to identify the determinants of plant species richness in the three wetland types and discern the transition of the determinants along a hydrological gradient. Plant species richness as well as area, habitat heterogeneity and resource availability was investigated in 51 wetland remnants, which were composed of 6 PIM, 25 SIM and 20 WM. Averagely, the area of wetland remnants occupied by PIM, SIM and WM was 0.35 ± 0.17 ha, 2.81 ± 2.88 ha and 1.34 ± 1.18 ha respectively. Aggregating the species in each wetland type, there were 67, 244 and 170 species recorded in PIM, SIM and WM. The determinants of species richness varied in different wetland types: standing water depth in PIM, area and water heterogeneity in SIM, and soil fertility and area in WM. With the decreasing water level, the influence of hydrological condition on species richness in the three wetland types declined while the impact of area and soil fertility gradually increased. Thus, hydrological condition was probably responsible for the transition of the determinants of species richness in different wetland types. Moreover, the habitat specialists of wetland would be lost when PIM or SIM degraded to WM. In order to conserve and restore plant diversity, specific measures should be taken including preventing area loss for all wetland remnants, managing the hydrological process for PIM and SIM, and regulating soil nutrient for WM.
3

Species abundance-distribution relationship: the differences among oak (Quercus liaotungensis Koidz) forest layers

88%
Feng Y., Ma K., Zhang Y., Anand M., He K.
Polish Journal of Ecology
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2011
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tom 59
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nr 1
Species abundance-distribution relationship is currently a hot topic in community ecology. Previous studies have suggested that a positive abundance-distribution relationship is a widespread feature of ecological assemblage across a wide variety of organisms, but how this relationship varies among different functional groups remains unclear. In this study, the species abundance-distribution relationship in the tree layer, shrub layer, and herb layer were analyzed respectively in an oak forest (Quercus liaotungensis Koidz.), Beijing region, China. Ten transects were set up from the foot to the top of every west slope to create a continuous altitude gradient (1020– 1770 m). The width of each transect was 10 m and the length of each transect ranged from 80–200 m, depending on the altitude range and slope degree. This study area consisted of 119 quadrats, each 10 × 10 m2. Within each quadrat, three sub-quadrats (1m × 1m) were randomly selected for the inventory of herb layer. Our results showed that the relationship between local species abundance and the regional distribution was significantly positive while the frequency distribution was unimodal in the three layers, indicating that locally abundant species were widely spread whereas locally rare species had restricted regional distributions. Variance partitioning of species abundance showed that the contribution of environmental variation and spatial variation to regulating the species abundance-distribution relationship of different layers are different: the pure geographical variation decreased and the pure soil variation increased in the order of tree layer, shrub layer, to herb layer, while the response due to total soil variation was similar in all three layer communities. The distribution of tree layer and shrub layer are mainly influenced by large-scale factors while herb layer distribution is more likely determined by local-scale factors.
4
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EGTA, a calcium chelator, affects cell cycle and increases DNA methylation in root tips of Triticum aestivum L.

88%
Zhang C., Shi W., Ma K., Li H., Zhang F.
Acta Societatis Botanicorum Poloniae
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2016
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tom 85
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nr 3
In this study, when germinated Triticum aestivum L. seeds were treated with 0, 2, 4 and 6 mM ethyl glycol tetraacetic acid (EGTA), root growth was suppressed and the mitotic index decreased. These inhibitory effects were positively correlated with EGTA concentration. RT-PCR analysis revealed that the expression of several gene markers related to the G1/S transition of the cell cycle were significantly downregulated. Confocal microscopy of Fluo-3/AM-stained roots showed chelation of nearly all of the Ca2+ within the root meristematic regions. Both random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques showed significant increases in the levels of genomic DNA polymorphisms and degree of DNA methylation. The study provides information concerning the impact of Ca²+) chelator, EGTA, on the growth, expression of cell cycle transition marker genes, and changes in DNA structure and methylation in the wheat roots.
5

Species similarity - distance relationship in wetlands: effect of disturbance intensity

88%
Lu T., Ma K., Zhang Y., Ni H., Fu B.
Polish Journal of Ecology
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2009
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tom 57
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nr 4
647-657
Disturbance is considered to be one of the main factors influencing variations in species diversity. While many experimental and observational studies provide a good understanding of how disturbance maintains the α-diversity, we know little about how disturbance influences β-diversity, and the effects of disturbance intensity on spatial species turnover are lacking. The aim of this paper is to evaluate the effects of disturbance on patterns of species similarity in wetland communities, and to identify how disturbance intensity affects the species similarity - distance relationship. In our study, four isolated wetland remnants under different agricultural drainage ditch densities were surveyed in Sanjiang Plain, Northeast China. Wetland disturbance was assessed by agricultural ditch densities, and species similarity was quantified by the Jaccard index. A simple measure of environmental distance was obtained by using water level and five soil variables, and a corresponding measure of geographical distance was made between pairs of plots from each site. Based on these data, we estimated rates of distance decay through regression of log-transformed compositional similarity against both environmental and geographical distance for pair-wise comparisons of wetland plots from each site. One key finding of our research is that disturbance intensity does influence the species similarity - distance relationship. At each site, species similarity decreased significantly with distance, and both effects of geographical and environmental distance were statistically significant. The results indicate that with disturbance intensity increasing, the distance decay rate decreases.
6

Diversity and composition of wetland communities along an agricultural drainage ditch density gradient

76%
LU T., Ma K., FU B., Zhang J., Lu Q., Hudson S.
Polish Journal of Ecology
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2009
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tom 57
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nr 1
113-123
Agricultural drainage ditches are a reflection of the disturbance caused by agriculture and other human perturbations associated with agricultural activities, and the density of them can be seen as an important gradient reflecting local disturbance. However, no studies to date have examined the changes in wetland communities in relation to drainage ditch densities, yet such information is urgently needed for the conservation of wetland ecosystems facing intensive cultivation. In this paper, we inventoried 67 plots at four wetland mosaics with the ditch density values ranged 0–3.6 km km⁻² in the Sanjiang Plain, and the species richness, composition and diversity were compared among those four sites. Linear regression was used to explore relationships between wetland community pattern and agricultural ditch density, and the results show that there is significant relationship (r² = 0.56, P <0.001). The diversity comparisons show that there exist a clear negative relationship between ditch density and species diversity indices, and the species diversity did not differ greatly among sites, but species composition varied considerably. With increasing ditch density, an increasing loss of indigenous wetland species paralleled with an increasing incursion of upland species. Management implication from the drainage ditches is that the density of 1.2 km km⁻² be the maximum value suitable for the protection of native wetlands in Sanjiang plain.
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