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1.

Mulberry (Morus spp.) is a cross-pollinating and highly hybridized plant of which productivity are greatly varied in different varieties. Accurate distinction among mulberry varieties and understanding of phylogenetic relationship among them would be crucial for the development of sericulture. We have analysed molecular distinction among four mulberry species and varieties cultivated in DPR Korea by using nuclear ribosomal internal transcribed spacer (ITS) sequences and inter simple sequence repeat (ISSR) markers. ITS sequences doesn’t represent a remarkable interspecific distinction among four mulberry species used in our study, suggesting that it could not be employed to identify them. ISSR analysis using 16 random primers generated 158 different markers ranging from 100 to 4000 bp in size. The results showed the inter-specific genetic variation (55.34%) was slightly higher than intra-specific genetic variation (44.66%), with comparatively low average number of migrants per generation (Nm) among populations (0.3886). Using ISSR primers selected in this study, in the future, the suitable breeding strategy might be established in raising of elite mulberry varieties on the basis of interspecific hybridization.

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2.
Ho  Un-Hyang  Song  Sam-Rang  Pak  Hak-Song  Kim  Kang  Ho  Tong-Su  Ju  Il-Yop 《Genetic Resources and Crop Evolution》2022,69(6):2105-2114
Genetic Resources and Crop Evolution - Japanese black pine (Pinus thunbergii Parl.) with high salt tolerance may be an important constitutive element sustaining terrestrial ecosystem by playing a...  相似文献   

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Journal of Soils and Sediments - The International Maritime Organization’s (IMO) International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM...  相似文献   

5.
Exploitation of wildlife for meat in the tropics (‘bushmeat’) is a critical threat for biodiversity, particularly in Africa. Here, we investigate the importance of protected areas (National Parks and other forest parks) as sources for the trade by exploring patterns in pricing and condition of bushmeat carcasses. We surveyed carcass prices in a large sample of trading points (87 markets surveyed, over a 35,000 km2 area) in Cameroon and Nigeria in the Cross–Sanaga region of West Africa. We assessed evidence for national parks as the source of animals traded as bushmeat. The study area included rural and urban centers (Calabar, Nigeria, and Douala, Cameroon) close to important protected areas: the Cross River National Park in Nigeria, and Korup National Park in Cameroon. Both parks host very high species diversity, including a range of endemics. Prices increased with distance from national park boundaries, particularly in Cameroon, where parks may be less depleted than in Nigeria. There was evidence that trading points closer to parks were more likely to function as wholesalers, with meat moving onto further trading points, rather than being sold to the end consumer. Carcasses were more often smoked (a treatment aimed at preservation) if they were not sold to their final consumers; smoking was also commoner at larger trading points. Prices were higher close to the road network, where opportunities for further trade were more available. We consider how wildlife harvests in and around protected areas may be managed to minimize depletion of animal populations, and if protected areas may, on the principle of marine no-take zones, be sustainable sources for regulated harvests.  相似文献   

6.
The study analyzed 108 films released during the transformation agenda period. The proportion, frequency, centrality and framing of agricultural content in the movies were reviewed. Data obtained were described using frequency counts and percentages. One out of three movies screened had agricultural content, which was either one or two scenes in the movie (80.0%). Such content was mostly peripheral (89.0%) to the themes of the films and negatively framed (60.0%). Potentials of the industry for agricultural purposes were poorly utilized by government. Government should partner with Nollywood to portray agriculture in a positive light for improved citizens’ attitude toward agriculture.  相似文献   

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Forest litter as a component of the carbon cycle in pine–broadleaved forests of different ages was characterized. Field studies of the forest site of the Primorskaya State Agricultural Academy in the south of the Sikhote Alin Range continued for three years. Multiple sampling of forest litter and plant litter fall and measurements of the CO2 emission from the litter and underlying soil horizons were performed on test plots. The maximum litter pool (14.44 ± 0.86 t/ha) was found in the mature stand of Pinus koraiensis; the minimum litter pool (11.52 ± 0.65 t/ha), in the 80-year-old stand. The carbon stock in the litters amounted to 3.7% of the phytomass carbon. The rate of carbon turnover in the forest litters was relatively low in comparison with that in other regions: the ratio of carbon pools in the litter horizons and annual plant falloff reached 3.5. The winter season provided about 10–25% of the annual plant litter fall. The data obtained in this study describe a part of the carbon cycle and contribute to our understanding of the ecosystem function of climate regulation by valuable forest massifs in the south of the Far East of Russia. In this region, the decomposition of forest litters generates the CO2 flux amounting up to 16% of the total CO2 emission from the soil.  相似文献   

9.

Purpose

This work explores the application of the use of Zn, Cu, and Pb relative contents as a new type of normalization method for geochemical properties of soils and sediments in an Atlantic Basin (Anllóns River, NW Spain). The method is based on the conservative behavior of these elements, which exhibit a certain concentration ratio that remains stable as long as there are no human disturbances.

Materials and methods

The average relative contents of Zn, Cu, and Pb were calculated by dividing the concentration of each metal in soils or sediments, in the <63-μm fraction, by the sum of Zn, Cu, and Pb, expressed as a percentage. The evaluation of the sum of the average relative concentrations of Zn, Cu, and Pb (Ri), together with three standard deviations for each element, namely, Ri ± 3Si, allows a hexagon to be constructed, represented in ternary diagrams of Zn:Cu:Pb. Following the method proposed by Weng et al. (Environ Geol 45:79–85, 2003), those samples falling outside the hexagon must be considered outliers.

Results and discussion

Results obtained confimed the conservative behavior between the relative contents of Zn, Cu, and Pb in surficial samples (soils, bed, and suspended sediments). Only sediment cores displayed nonconservative behavior, showing a marked Pb enrichment, with respect to the surficial samples. When Zn, Cu, and Pb relative contents were plotted in ternary diagrams, outliers were best classified when the hexagon was drawn with standard deviations of samples from the study area. The hexagon drawn with an international database of soils and sediments showed a poorer classification of outliers.

Conclusions

The results showed that total Zn, Cu, and Pb relative contents may be employed to investigate anthropogenic disturbances of these elements in soils and sediments of the Anllóns River Basin, thus corroborating that this type of normalization may be employed as a tool to assess outliers in a contaminated area.  相似文献   

10.

Distinguishing among commercial varieties or accessions in a germplasm repository presents considerable challenges when dealing with common crops or large collections. In the genus Pisum L. the third intron of the gene STAYGREEN (SGR), responsible for the green/yellow cotyledon variation, contains a complex of repeat sequences that display considerable indel and single nucleotide (SNP) polymorphism. In a sample of 137 Pisum L. accessions obtained from various germplasm collections 76 alleles were identified, ranging from about 600 to 1500 nucleotides in length. In most cases alleles differed by insertion/deletion (indel) polymorphisms in addition to single base changes. The amplicon was particularly useful for distinguishing wild accessions (those with dehiscent pods and dormant seeds). Among the 51 P. sativum L. accessions examined with a definite wild phenotype there were 44 SGR alleles. When this allelic variation was combined with location data for the wild accessions, each allele could be assigned a unique geographical location. Similarly, of the 10 P. fulvum Sibth. & Sm. accessions analyzed, only a group of three had the same allele, two of which are known to be replicates. We were able to confirm the identities of several P. sativum accessions from different germplasm collections, as well as identifying two cases where supposedly synonymous accessions gave different intron sequences. In addition, a group of wild pea accessions from Greece, Sicily, and Portugal exhibited a unique repeat sequence not found in any other wild accession, suggesting that these accessions constitute a distinct lineage. The rate of nucleotide site variation in this fragment of the SGR locus was found to be about 2.22 × 10–8 substitutions per site per year. This value is similar to those found for many other sequences in herbaceous papilionoid tribes, although it is at the faster end of the distribution of herbaceous legume substitution rates. We propose that both a fast substitution rate as well as the formation and rearrangement of indels have contributed to the high level of variation we detected at SGR. This PCR product should prove valuable in the identification of Pisum accessions, for quality control operations in germplasm repositories, and for exploring the evolutionary relationships within the genus.

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The morphology and properties of the soils of permafrost peatlands in the southeast of the Bol’shezemel’skaya tundra are characterized. The soils developing in the areas of barren peat circles differ from oligotrophic permafrost-affected peat soils (Cryic Histosols) of vegetated peat mounds in a number of morphological and physicochemical parameters. The soils of barren circles are characterized by the wellstructured surface horizons, relatively low exchangeable acidity, and higher rates of decomposition and humification of organic matter. It is shown that the development of barren peat circles on tops of peat mounds is favored by the activation of erosional and cryogenic processes in the topsoil. The role of winter wind erosion in the destruction of the upper peat and litter horizons is demonstrated. A comparative analysis of the temperature regime of soils of vegetated peat mounds and barren peat circles is presented. The soil–geocryological complex of peat mounds is a system consisting of three major layers: seasonally thawing layer–upper permafrost–underlying permafrost. The upper permafrost horizons of peat mounds at the depth of 50–90 cm are morphologically similar to the underlying permafrost. However, these layers differ in their physicochemical properties, especially in the composition and properties of their organic matter.  相似文献   

13.
ABSTRACT

Pedotransfer functions (PTFs), as an indirect forecasting method, offer an alternative for labor-intensive bulk density (BD) measurements. In order to improve the forecasting accuracies, support vector machine (SVM) method was first used to develop PTFs for predicting BD. Cross-validation and grid-search methods were used to automatically determine the SVM parameters in the forecasting process. Soil texture and organic matter content were selected as input variables based on results of predecessors, coupled with gray correlation theory. And additional properties were added as inputs for improving PTF's accuracy and reliability. The performance of the PTF established by SVM method was compared with artificial neural network (ANN) method and published PTFs using two indexes: root-mean-square error (RMSE) and coefficient of determination(R2). Results showed that the average RMSE of published PTFs was 0.1053, and the R2 was 0.4558. The RMSE of ANN–PTF was 0.0638, and the R2 was 0.7235. The RMSE of SVM–PTF was 0.0558, and the R2 was 0.7658. Apparently, the SVM–PTF had better performance, followed by ANN–PTF. Additionally, performances could be improved when accumulated receiving water was added as predictor variable. Therefore, the first application of SVM data mining techniques in the prediction of soil BD was successful, improved the accuracy of predictions, and enhanced the function of soil PTFs. The idea of developing PTFs using SVM method for predicting soil BD in the study area could provide a reference for other areas.  相似文献   

14.
More than 100?years ago, before the rediscovery of Mendel’s laws of inheritance, Nazareno Strampelli started a deliberate crossing programme among Italian and foreign bread wheat genotypes that led to the constitution of over 100 varieties and allowed Italy to significantly increase wheat production. Several varieties enjoyed worldwide popularity and were instrumental in the success of many other breeding programmes. To better understand the reasons of these accomplishments, 84 accessions, representing 50 Strampelli varieties, were characterized for glutenin storage proteins and AFLP patterns, in order to confirm their identification and to assess their genetic diversity. The molecular markers analysis confirmed the correct attribution of most accessions and highlighted the broad genetic variation existing among Stampelli’s varieties. Some genotypes, deemed incompatible with the available pedigree data, were removed from the final analysis. A limited within-variety diversity among genotypes was probably due to incomplete homogeneity and stability of Strampelli materials, but also to the use of heterogeneous local populations as parents.  相似文献   

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16.
Land Use and Soil Organic Carbon in China’s Village Landscapes   总被引:2,自引:0,他引:2  
Village landscapes, which integrate small-scale agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across China. Village lands tend to be managed at very fine spatial scales (≤ 30 m), with managers both adapting their practices to existing variation in soils and terrain (e.g., fertile plains vs. infertile slopes) and also altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Relationships between fine-scale land management patterns and soil organic carbon (SOC) in the top 30 cm of village soils were studied by sampling soils within fine-scale landscape features using a regionally weighted landscape sampling design across five environmentally distinct sites in China. SOC stocks across China’s village regions (5 Pg C in the top 30 cm of 2 × 10 6 km 2 ) represent roughly 4% of the total SOC stocks in global croplands. Although macroclimate varied from temperate to tropical in this study, SOC density did not vary significantly with climate, though it was negatively correlated with regional mean elevation. The highest SOC densities within landscapes were found in agricultural lands, especially paddy, the lowest SOC densities were found in nonproductive lands, and forest lands tended toward moderate SOC densities. Due to the high SOC densities of agricultural lands and their predominance in village landscapes, most village SOC was found in agricultural land, except in the tropical hilly region, where forestry accounted for about 45% of the SOC stocks. A surprisingly large portion of village SOC was associated with built structures and with the disturbed lands surrounding these structures, ranging from 18% in the North China Plain to about 9% in the tropical hilly region. These results confirmed that local land use practices, combined with local and regional variation in terrain, were associated with most of the SOC variation within and across China’s village landscapes and may be an important cause of regional variation in SOC.  相似文献   

17.

Purpose  

Village landscapes, which integrate small-scale agriculture with housing, forestry and a host of other land use practices, cover more than 2 × 106 km2 across China. Village lands tend to be managed at very fine spatial scales (≤30 m), with managers altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Under these conditions, accumulation of excess phosphorous in soils has become important contributor to eutrophication of surface waters across China’s densely populated village landscapes. The aim of this study was to investigate relationships between fine-scale patterns of agricultural management and soil total phosphorus (STP) within China’s village landscapes.  相似文献   

18.
This study reports on the concentrations, distribution, and availability of heavy metals in the children’s playground soils of Athens. Playgrounds were chosen because they are open city areas; they show relatively even spatial distribution within the district of Athens and are used by a great number of young children and their escorts on a regular basis. Samples were collected from 70 playground surface soils, representing more than 70% of the city’s playgrounds. Cu, Zn, Pb, Cr, Ni, Co, Mn, and Fe were extracted by aqua regia and by diethylene triamine pentaacetic acid (DTPA) to estimate total and available metal forms, respectively. Their mean total concentrations were 43, 174, 110, 80, 82, 22, 312, and 17?×?103?mg kg?1, respectively. The DTPA-extracted fraction showed much lower values, with means of 2.5, 7.8, 5.8, 1.5, 1.3, 0.4, 8.4, and 2.0 mg kg?1 respectively, which, however, should be carefully monitored since they relate directly to the bioavailable fraction of heavy metals. Though mean values of metal concentrations are not particularly high, the calculated enrichment factors indicate site-specific cases of high enrichment with heavy metals. Considering that the bioavailable fraction of a metal is possibly a more appropriate indicator for the recent soil pollution history, availability ratios were calculated and their distribution was visualized over the entire city profile using the appropriate GIS software. It was shown that recent metal pollution events appear to have affected mostly playground sites in the southern and eastern part of the municipality.  相似文献   

19.
The last two decades have seen a rise of interest in the adoption and diffusion of agricultural technologies aimed at improving the sustainability of agricultural lands among smallholder farmers in developing countries. This papers set out to understand factors that influence the adoption of technologies that enhance soil carbon sequestration among smallholder farmers, using secondary data recorded in the World Overview of Conservation Approaches and Technologies (WOCAT) database from 45 to 50 smallholders’ farmers in selected places in Kenya and Ethiopia respectively. A Probit model was used to analyse whether socio-economic, institutional, off-farm income, technical know-how, farmers’ perceptions, and land use characteristics influences the adoption of technologies that enhance soil carbon sequestration. The results show that smallholder farmers that positively perceived net benefits of the soil carbon enhancing technologies were more likely to adopt such technologies that enhance soil carbon sequestration in both countries. Access to off-farm income and land ownership with title deeds were also found to be positively associated with adoption. Off-farm income positively influences adoption among farmer with a moderate income (100-500US$ per year) but not the rich (>500US$) farmers. Moderate to high level of skills and technical know-how required for implementing and maintaining a technology on the farm had a negative influence on adoption. This shows that interventions, aimed at addressing specific factors such as inadequate skills and knowledge, change in perception among farmers, and off-farm income are likely to have the greatest impact in decisions relating to the adoption of the soil carbon enhancing practices among farmers in East Africa.  相似文献   

20.
Lupachev  A. V.  Gubin  S. V.  Gerasimova  M. I. 《Eurasian Soil Science》2019,52(10):1170-1174
Eurasian Soil Science - The paper is targeted at positioning the cryogenic soils in the recent classification system of Russian soils. An on-line discussion and recent publications demonstrated...  相似文献   

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