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1

Ecological adaptation strategies in alien species: effects of salinity, temperature and photoperiod on Spartina alterniflora Loisel. seed germination

100%
Yuan Z., Shi F.
Polish Journal of Ecology
|
2009
|
tom 57
|
nr 4
677-683
Spartina alterniflora (smooth cordgrass), a perennial grass native to the coastal marshes of eastern America, is widely distributed in northern China since 1979 of its introduction. In the tidal marshlands of north China, S. alterniflora has displaced native species and is presently dominant member of the community owing to its opportunistic characteristics. In this study we investigated S. alterniflora seed germination responses to different temperatures, between 5–25ºC in one thermoperiod (16/26ºC) and in two light treatments – 10/14h (night/day) photoperiod and dark conditions. Variations of seed germination at different storage temperatures and storage duration were also examined. In addition, the effect of different salt concentrations on seed germination was evaluated. The optimal temperature for germination was 25ºC and 16/26ºC (night/day) thermo-period – germination percentage was greater than 90%. Light intensity had no influence on the percent of seed germination and germination indices when seeds were exposed to identical temperatures. At 120 d of storage and -5, 0, and 5ºC temperatures, germination percentage exceeded 75%. The optimal salinity level for seed germination was 150 mM NaCl. Germination percentages were highest (> 90%) when salinity did not exceed 450 mM NaCl. The ability of S. alterniflora seeds to germinate under a wide range of temperature and light conditions resulted in continued seedling development under high salinity.
2

Effects of livestock exclusion on vegetation and soil properties under two topographic habitats in an Alpine meadow on the Eastern Quinghai - Tibetan Plateau

81%
Shi F., Chen H., Wu Y., Wu N.
Polish Journal of Ecology
|
2010
|
tom 58
|
nr 1
Long-term overgrazing has resulted in grassland deterioration and even desertification on the eastern Qinghai-Tibetan Plateau. In this paper, we examined the characteristics of vegetation and soil properties in the livestock-excluded pastures and the adjacent grazed pastures under two topographic habitats (the flat valley and the south-facing slope). Seven-year exclusion of livestock has enhanced aboveground live biomass, root biomass and litter accumulation. Livestock exclusion has also increased soil bulk density and soil water content, soil organic C concentration, total N concentration and its transformation rate, and soil microbial activity. The results showed that livestock exclusion has facilitated vegetation recovery and improved physical, chemical and biological properties of soil. However, livestock exclusion has significantly decreased graminoid biomass accumulation, especially on the flat valley, the biodiversity also significantly decreased there. The results suggested that long-term livestock exclusion was disadvantageous for palatable forage production and biodiversity protection on the flat valley. Compared to the flat valley, the grassland on the south-facing slope was under more severe degradation, and the reversion was in a slower process. Thus, the optimal grassland management in the livestock-excluded pasture on the flat valley should include a low or moderate grazing intensity or adopt an alternate grazing system, but more effective and even longer livestock exclusion practice should be taken on the south-facing slope.
3

About non-bilayer phases in the mechanism of lipoplex-mediated gene delivery

80%
Hoekstra D., Rejman J., Shi F., Zuhorn I.
Cellular and Molecular Biology Letters
|
2005
|
tom 10
|
nr Suppl.
4

The ecological profit in phenology and pollination of alien species Spartina alterniflora [Loisel] introduced to coastal wetlands in Northern China

71%
Shi F., Yuan Z., He K. S., Li J., Guo S.
Polish Journal of Ecology
|
2009
|
tom 57
|
nr 2
283-289
For the plant species, effective phenology and pollination syndromes can increase viable seeds which enhance the species to colonize new areas. So the species with a suit of advantageous characteristics inherent in its reproductive ecology is critical to its dispersion. Spartina alterniflora – a perennial grass native to coastal marshes of America was introduced to China in 1979 and now it is distributed in the Tianjin coastal wetlands of northern China. Flowering phenology was examined and indicated that in northern localities, flowering initiated in mid-August and senescence occurred by the end of October. The pollen-ovule ratio was 9875 (±2150). Abundant pollen grains compensated for a lack of pollen viability. Pollen viability was 10% approximately when pollen released 4 hours, but stigma receptivity was above 10% when stigmas exserted 7 hours. Stigmas maintained viability longer than the period of pollen release, ensuring successful pollination. Scanning electron microscopy was used to observe stigma surface characters and pollen viability. Further investigation proved stigma adaptations to increase pollen capture and exterior pollen tube growth following pollination was beneficial to fertilization. The results suggested that flowering phenology and pollination traits are vital to pollination and production of viable seed, enabling the species to spread rapidly and succeed in new habitats of northern China.
5

Wet deposition of heavy metals in an arid city

71%
Liu Y., Liu C., Tian F., Liu H., Shi F.
Polish Journal of Environmental Studies
|
2015
|
tom 24
|
nr 3
In order to investigate characteristics of wet deposition of heavy metals in an arid city, precipitation samples were collected for 16 precipitation events in the arid city of Changji. A total of 16 samples were collected and concentrations of principal heavy metals in the atmosphere were examined by inductively coupled plasma-mass spectrometry (ICP-MS) to discuss levels, variation, and wet deposition fluxes of heavy metals. Among these heavy metals in wet deposition, Fe, Zn, and Cu were found to be the highest. Levels of As, Ni, and Cr ranked second, while Pb, Cd, and Hg were found to be the lowest. The concentrations of heavy metals in wet deposition showed distinct seasonal variations, having high values in winter and low values in other seasons. Besides, in general, concentrations of heavy metals in snow were higher than those in rain. Because the winter was cold and long in Xinjiang, emissions from coal-fired heating were high, which was associated with enhanced concentrations of heavy metals. The order of wet deposition fluxes of heavy metals in the whole year was Fe > Cu, Zn > As, Ni, Cr, Pb > Cd, Hg. Compared to other areas, wet deposition fluxes of heavy metals were low in Changji, which may be due to minimal rainfall in the arid city, having a weak scavenging effect of atmospheric pollutants. In addition, because the level of urbanization and industrialization was not high in Changji, emissions of atmospheric pollutants were low.
6

Size distribution of atmospheric particulates and Pb concentrations in TSP during the cold-weather heating period

61%
Liu Y., Liu C., Shen Y., Tian F., Liu H., Shi F.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 1
We collected and analyzed atmospheric particulates in Changji, China, in order to investigate size distribution of atmospheric particulates and Pb concentrations in TSP during cold-weather heating periods. The results indicated that during such periods, contamination increased as particle size decreased. As compared with the non-heating period, the concentrations of atmospheric particulates were relatively higher during the heating period. The concentrations of TSP, PM10, PM5, and PM2.5 had two peaks during this time. Coal combustion and meteorological variables – especially temperature – could be the main contributing factors. The size distribution of atmospheric particulates had certain regularity. The ratio of atmospheric particulates with size under 2.5 μm in TSP first increased and then decreased during the heating period. Atmospheric particulates with size between 2.5 to 5, 5 to 10, and 10 to 100 μm in TSP had the same change trend of first decreasing and then increasing. The change in the Pb trend was contrary to the temperature during the heating period, which may be caused by the fact that as temperature decreased, the intensity of coal combustion for heating increased, which emitted a lot of Pb. Conducting this study plays a significant role in prevention and control of atmospheric pollution and ecological environmental protection.
7

Growth and physiological responses to copper stress in a halophyte Spartina alterniflora (Poaceae)

61%
Chai M., Shi F., Li R., Qiu G., Liu F., Liu L.
Acta Physiologiae Plantarum
|
2014
|
tom 36
|
nr 03
A study quantifying the effects of different copper (Cu) concentrations (50, 200, 800 and 1,000 mg kg⁻¹ Cu) on Cu bioaccumulation and physiological responses of Spartina alterniflora was conducted. Plant biomass and Cu accumulation were determined. Plant height, tiller number, chlorophyll, leaf electrolyte leakage rate (ELR), malondialdehyde (MDA), proline, soluble sugar, and organic acids were also measured. The results showed that S. alterniflora mainly accumulated Cu in fine roots. No significant changes of biomass of fine roots were detected except for obvious reduction under 1,000 mg kg⁻¹ Cu. In leaves, rhizomes and fine roots, the highest Cu accumulations were detected under 800 mg kg⁻¹ Cu. The highest Cu accumulation in stem was revealed under 200 mg kg⁻¹ Cu. Plant height decreased under 1,000 mg kg⁻¹ Cu; chlorophyll content reduced under >50 mg kg⁻¹ Cu; levels of ELR and MDA increased under >200 mg kg⁻¹ Cu. However, osmotic components such as proline and soluble sugar were accumulated to cope with higher Cu stresses (800 and 1,000 mg kg⁻¹ ). Further, oxalic and citric acids were positively related with Cu contents in leaves and stems, suggesting that oxalic and citric acids may be related to Cu detoxification in aboveground parts of S. alterniflora. However, in above and belowground parts, no detoxification function of ascorbic and fumaric acids was observed due to unchanged or decreased trend under Cu stress.
8

Nitric oxide and thyroid hormone receptor alpha 1 contribute to ovarian follicular development in immature hyper- and hypo-thyroid rats

61%
Zheng K., Sulieman F. J., Li J., Wei Q., Xu M., Shi F.
Reproductive Biology
|
2015
|
tom 15
|
nr 1
9

Allometric partitioning theory versus optimal partitioning theory: the adjustment of biomass allocation and internal C-N balance to shading and nitrogen addition in Fritillaria unibracteata (Liliaceae)

61%
Guo H., Xu B., Wu Y., Shi F., Wu C., Wu N.
Polish Journal of Ecology
|
2016
|
tom 64
|
nr 2
Fritillaria unibracteata is a classic perennial alpine herb. In this study, we examined it's responses to shading (SH) and nitrogen addition (NA), as well as its correlation with internal C-N balance to detect how it adjusted to the changes of habitat conditions. Randomized block experiment was carried out in the field in Chuanbeimu Research Station in Songpan County, Sichuan Province, China (32°09′54″N, 103°38′36″E, altitude 3300 m a.s.l.). Two growing seasons after NA and SH, Fritillaria unibracteata's total plant biomass decreased significantly, with the proportion of biomass allocated to aboveground significantly increased. In addition, in this study, under both SH and NA treatments, Fritillaria unibracteata increased its biomass allocation to above-ground, which consisted with optimal partitioning theory. Moreover, Fritillaria unibracteata's biomass allocation was significantly correlated with its internal C-N status, regardless of nitrogen and light condition. We conclude that Fritillaria unibracteata optimizes its biomass allocation between root and shoot by adjusting its internal C-N balance, which would not be changed by the specialized resource storage organ-bulb.
10

Effects of saline-alkaline stress on early growth strategy and colonization success of Flaveria bidentis ( L.) Kuntze (Asteraceae ) - a new exotic plant in Northern China

61%
Chai M., Shi F., He K. S., Li R., Cao D., He Z.
Polish Journal of Ecology
|
2012
|
tom 60
|
nr 3
Flaveria bidentis, an annual grass native to South America, has invaded into many countries all over the world, including South Africa and Egypt in Africa, Britain and France in Europe, Japan in Asia, and Australia. In China, this plant species has been widely distributed in Hebei province since 2001 of its first discovery in Tianjin. In salinized soil of northern China, F. bidentis has formed mono dominant communities owing to its opportunistic characteristics. In this study, we investigated germination rate, germination energy, germination index and vigor index in response to different saline-alkaline stresses. Lengths of seedling, hypocotyl, and radicle were also examined. During germination process, germination rate, germination energy, germination index, and vigor index decreased due to higher salinity and alkalinity (pH). Hypocotyl elongation was stimulated at low salinity and alkalinity, but decreased with increasing salinity and alkalinity. The lengths of radicle and seedling were inhibited sharply with increasing salinity and alkalinity. These results suggest that a reciprocal enhancement between salt stress and alkaline stress was a characteristic feature during seed germination of F. bidentis. Ungerminated seeds resumed to germinate after transferred to distilled water, indicating that seeds remained viable during their exposure to saline-alkaline stresses. Stepwise regression analysis indicated that the effects of salinity, alkalinity (pH), and buffer capacity on seed germination and seedling growth were significantly different in magnitude. Salinity and alkalinity (pH) were the dominant factors in seed germination and seedling growth of F. bidentis respectively. burther, the results of this study suggest that F. bidentis has developed excellent adaptative strategy in its early stage of life cycle which partially explains its current invasion success in northern China.
11

Sweet taste receptor agonists alter ovarian functions and ovarian cycles in aged mice

51%
Kavita Ngekure M. X., Jiang J., Enayatullah H., Ennab W., Mustafa S., Rodeni S., Wei Q., Shi F.
Reproductive Biology
|
2019
|
tom 19
|
nr 3
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