[Objective] The aim was to study on the genetic diversity of local varieties of Chinese Hu mulberry (Morus L.). [Method] The genetic diversity of 141 copies of Hu mulberry varieties was analyzed by ISSR molecular mark...[Objective] The aim was to study on the genetic diversity of local varieties of Chinese Hu mulberry (Morus L.). [Method] The genetic diversity of 141 copies of Hu mulberry varieties was analyzed by ISSR molecular markers. [Result] 12 ISSR primers had amplified a total of 90 amplified,of which 57 bands were polymorphic,and the polymorphic rate was 63.33%. The genetic similarity coefficients of 141 Hu mulberry germplasm resources varied from 0.633 3 to 1.000 0 with the average of 0.483 35,indicating that there was difference on genetic diversity among different varieties of Hu mulberries. A dendrogram of all 141 Hu mulberry varieties based on the genetic similarity coefficients using ISSR molecular markers was generated by UPGMA cluster method. Clustering of the 141 Hu mulberry varieties did not correspond with the conventional classification involving differences in style,leaf,branch,fruit and other morphological or agronomical characters. [Conclusion] Four subgroups clearly represented the genetic relationships in the 141 accessions which were benefit for the variety improvement and germplasm resource conservation.展开更多
The present study is conducted in the scenario of the tannery waste hazards in Kasur district of Pakistan where the tannery industry is considered as major cause of groundwater quality deterioration, Area focused in t...The present study is conducted in the scenario of the tannery waste hazards in Kasur district of Pakistan where the tannery industry is considered as major cause of groundwater quality deterioration, Area focused in this research constitutes the surroundings of the effluent carrying drains near tannery units. This study includes soil explorations, groundwater monitoring and wastewater analysis in the research area so as to find out the contamination extent of chromium in subsurface. Initial groundwater monitoring exhibited chromium concentrations as high as 90 mg/L in the tannery area. Even groundwater sampling from monitoring wells installed in the adjacent areas of effluent carrying drains, showed concentrations up to 10.4 mg/L. Wastewater analysis of all the drains in the research area has evidenced potential risk of contaminant seepage into soil and groundwater as level of chromium in wastewater samples has reported to be immensely high and varies from 68 mg/L to 2,152 mg/L. However the 30 soil samples collected from two soil bores did not show any significant results as the maximum values obtained for hexavalent chromium for leaching and retained in soil are 0.02 mg/L and 8.1 mg/kg, respectively. These low concentrations of soil samples suggest that the soil contamination may not be a main environmental issue in the areas adjacent to the effluent carrying drains, The research concludes as possibility of direct interference of the tannery wastewater with groundwater through damaged structures and sewers.展开更多
Changping Plain, located in the northwest of Beijing, has become an important groundwater recharge area for the Beijing Plain and an important source for the urban water supply. In this study, groundwater samples were...Changping Plain, located in the northwest of Beijing, has become an important groundwater recharge area for the Beijing Plain and an important source for the urban water supply. In this study, groundwater samples were collected during the dry and wet seasons in 2015 from 24 monitoring wells distributed in Changping Plain. A Piper-Tri-linear diagram, a Schoeller diagram, a Gibbs diagram, and the isotope technique were used to investigate the temporal and spatial variations in the concentrations of groundwater hydrochemicals and the sources of groundwater recharge. The results indicated： 1） seasonal variations in the concentrations of HCO3^–, Ca^2＋, and Na^＋ were significant; the spatial variations of these ions were more dramatic in the dry season than in the wet season due to the dilution effect of precipitation; 2） Most groundwater samples had a HCO3-Ca-Mg based hydrochemical type and a few had a HCO3-Na-K based hydrochemical type; the hydrochemical type tended to evolve from HCO3-Ca-Mg based to HCO3-Na-K based in some monitoring wells that showed distinct seasonal variation; 3） the groundwater in the study area originated mainly from atmospheric precipitation, and it is affected by evaporation and concentration processes.展开更多
Ecological niche modeling has emerged as an useful tool in the investigation of the phylogeographic histories of species or communities in a region. The high biodiversity （oftentimes cryptic）, and complex geography ...Ecological niche modeling has emerged as an useful tool in the investigation of the phylogeographic histories of species or communities in a region. The high biodiversity （oftentimes cryptic）, and complex geography and geological history of Southeast Asia particularly call for multipronged approaches in phylogeographic investigations. Past studies have focused on taxa that are associated with lowland rainforests, which is the dominant natural vegetation type. Here, we combine published phylogenetic data, ecological niche modeling and paleo-climate models to reveal potential drivers of divergence in two open-forest bird species, the oriental magpie-robin Copsychus saularis and Coppersmith barbet Megalaima haemacephala. In spite of broad overlap in current distributions, there are subtle differences in their climatic niches, which result in different responses to past climatic changes. For C saularis, both Last Glacial Maximum climate models indicated that the entire Sundaland was climati- cally suitable, while phylogenetic analyses found divergent eastern and western Sundaland lineages. We thus postulate that this genetic divergence was a result of past separations of coastal habitats into eastern and western portions due to the emergence of Sunda shelf as sea-level fell. The current separation of morphological subspecies in Borneo is maintained by low climatic suitability （high annual rainfall） in certain regions. The extirpation of M. haemacephala from Borneo and southern Malay Peninsula might have been driven by unsuitable conditions （high temperature seasonality） in central Sundaland and/or the lack of open woodlands. Our study shows that ecological niche modeling adds a powerful dimension to our attempt to understand lineage evolution in space [Current Zoology 61 （5）： 922-934, 2015].展开更多
基金Supported by National Science and Technology Infrastructure(2005DKA21002-09)
文摘[Objective] The aim was to study on the genetic diversity of local varieties of Chinese Hu mulberry (Morus L.). [Method] The genetic diversity of 141 copies of Hu mulberry varieties was analyzed by ISSR molecular markers. [Result] 12 ISSR primers had amplified a total of 90 amplified,of which 57 bands were polymorphic,and the polymorphic rate was 63.33%. The genetic similarity coefficients of 141 Hu mulberry germplasm resources varied from 0.633 3 to 1.000 0 with the average of 0.483 35,indicating that there was difference on genetic diversity among different varieties of Hu mulberries. A dendrogram of all 141 Hu mulberry varieties based on the genetic similarity coefficients using ISSR molecular markers was generated by UPGMA cluster method. Clustering of the 141 Hu mulberry varieties did not correspond with the conventional classification involving differences in style,leaf,branch,fruit and other morphological or agronomical characters. [Conclusion] Four subgroups clearly represented the genetic relationships in the 141 accessions which were benefit for the variety improvement and germplasm resource conservation.
文摘The present study is conducted in the scenario of the tannery waste hazards in Kasur district of Pakistan where the tannery industry is considered as major cause of groundwater quality deterioration, Area focused in this research constitutes the surroundings of the effluent carrying drains near tannery units. This study includes soil explorations, groundwater monitoring and wastewater analysis in the research area so as to find out the contamination extent of chromium in subsurface. Initial groundwater monitoring exhibited chromium concentrations as high as 90 mg/L in the tannery area. Even groundwater sampling from monitoring wells installed in the adjacent areas of effluent carrying drains, showed concentrations up to 10.4 mg/L. Wastewater analysis of all the drains in the research area has evidenced potential risk of contaminant seepage into soil and groundwater as level of chromium in wastewater samples has reported to be immensely high and varies from 68 mg/L to 2,152 mg/L. However the 30 soil samples collected from two soil bores did not show any significant results as the maximum values obtained for hexavalent chromium for leaching and retained in soil are 0.02 mg/L and 8.1 mg/kg, respectively. These low concentrations of soil samples suggest that the soil contamination may not be a main environmental issue in the areas adjacent to the effluent carrying drains, The research concludes as possibility of direct interference of the tannery wastewater with groundwater through damaged structures and sewers.
基金National Natural Science Foundation of China(41572240)
文摘Changping Plain, located in the northwest of Beijing, has become an important groundwater recharge area for the Beijing Plain and an important source for the urban water supply. In this study, groundwater samples were collected during the dry and wet seasons in 2015 from 24 monitoring wells distributed in Changping Plain. A Piper-Tri-linear diagram, a Schoeller diagram, a Gibbs diagram, and the isotope technique were used to investigate the temporal and spatial variations in the concentrations of groundwater hydrochemicals and the sources of groundwater recharge. The results indicated： 1） seasonal variations in the concentrations of HCO3^–, Ca^2＋, and Na^＋ were significant; the spatial variations of these ions were more dramatic in the dry season than in the wet season due to the dilution effect of precipitation; 2） Most groundwater samples had a HCO3-Ca-Mg based hydrochemical type and a few had a HCO3-Na-K based hydrochemical type; the hydrochemical type tended to evolve from HCO3-Ca-Mg based to HCO3-Na-K based in some monitoring wells that showed distinct seasonal variation; 3） the groundwater in the study area originated mainly from atmospheric precipitation, and it is affected by evaporation and concentration processes.
文摘Ecological niche modeling has emerged as an useful tool in the investigation of the phylogeographic histories of species or communities in a region. The high biodiversity （oftentimes cryptic）, and complex geography and geological history of Southeast Asia particularly call for multipronged approaches in phylogeographic investigations. Past studies have focused on taxa that are associated with lowland rainforests, which is the dominant natural vegetation type. Here, we combine published phylogenetic data, ecological niche modeling and paleo-climate models to reveal potential drivers of divergence in two open-forest bird species, the oriental magpie-robin Copsychus saularis and Coppersmith barbet Megalaima haemacephala. In spite of broad overlap in current distributions, there are subtle differences in their climatic niches, which result in different responses to past climatic changes. For C saularis, both Last Glacial Maximum climate models indicated that the entire Sundaland was climati- cally suitable, while phylogenetic analyses found divergent eastern and western Sundaland lineages. We thus postulate that this genetic divergence was a result of past separations of coastal habitats into eastern and western portions due to the emergence of Sunda shelf as sea-level fell. The current separation of morphological subspecies in Borneo is maintained by low climatic suitability （high annual rainfall） in certain regions. The extirpation of M. haemacephala from Borneo and southern Malay Peninsula might have been driven by unsuitable conditions （high temperature seasonality） in central Sundaland and/or the lack of open woodlands. Our study shows that ecological niche modeling adds a powerful dimension to our attempt to understand lineage evolution in space [Current Zoology 61 （5）： 922-934, 2015].
