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1.
The Food Quality Protection Act (FQPA) was enacted in August 1996 and required the US Environmental Protection Agency (EPA) to reassess all existing and new crop protection active substances using a new set of health and environmental standards to further protect infants and children. The initial fear that many minor or specialty crop use registrations would be lost without adequate replacements has largely been overcome by an aggressive programme by the International Research Project no. 4 (IR-4) in partnership with the EPA and the crop protection industry to register new, safer, reduced risk products for specialty crop pest control needs. Since the FQPA, the EPA has approved over 5600 new specialty crop uses resulting from IR-4 residue programmes. This amounts to about 56% of the over 10 000 clearances received by the IR-4 programme in its 43 year history and about 50% of all new uses granted by the EPA since FQPA. The positive outcomes from these efforts have been partially negated by the lack of tolerances or Maximum Residue Levels (MRLs) in countries to which US produce is exported. This has forced some US specialty crop growers to continue to use older, less desirable products. IR-4 has been addressing this challenge by cooperating in the NAFTA (North American Free Trade Agreement) countries with Agriculture and Agri-Food Canada's Pest Management Centre and Health Canada's Pest Management Regulatory Agency to harmonize MRLs through joint projects and regulatory reviews. IR-4 has also provided leadership for the International Crop Grouping Consulting Committee to harmonize specialty/minor crop groupings and representative crops for residue studies with the long-term goal being to globally harmonize MRLs.  相似文献   

2.

BACKGROUND

As the population and range of wild pigs (Sus scrofa) continue to grow across North America, there has been an increase in environmental and economic damages caused by this invasive species, and control efforts to reduce damages have increased concomitantly. Despite the expanding impacts and costs associated with population control of wild pigs, the extent to which wild pig control reduces populations and diminishes environmental and agricultural damages are rarely quantified. The goal of this study is to quantify changes in wild pig relative abundance and subsequent changes in damages caused by invasive wild pigs in response to control.

RESULTS

Using a combination of wild pig population surveys, agricultural damage assessments, and environmental rooting surveys across 19 mixed forest-agricultural properties in South Carolina, USA, we quantified changes in wild pig relative abundance and associated damages over a 3-year period following implementation of a professional control program. Following implementation of control efforts, both the number of wild pig detections and estimated abundance decreased markedly. Within 24 months relative abundance was reduced by an average of ~70%, which resulted in a corresponding decline in environmental rooting damage by ~99%.

CONCLUSION

Our findings suggest that sustained wild pig control efforts can substantially reduce wild pig relative abundance, which in turn resulted in a reduction in environmental rooting damage by wild pigs. Ultimately this study will help fill critical knowledge gaps regarding the efficacy of wild pig control programs and the effort needed to reduce impacts to native ecosystems, livestock, and crops. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

3.
This study aimed to reveal the microbial diversity in the fecal samples of bactrian camels using the 16 S r RNA sequencing analysis on the Illumina Mi Seq platform. Three fecal samples were collected from two geographical regions in China. Operational taxonomic unit(OTU) clustering was performed by identifying an OTU at 97% sequence identity. The alpha and beta diversities were applied to estimate the differences in microbial diversity among the three fecal samples. Totally, 4409, 3151 and 4075 OTUs in the fecal samples were identified in the Lop Nor wild camel(Camelus ferus), the domestic camel(C. bactrianus) and Dunhuang wild camel(C. ferus), respectively. The majority of bactreria were affiliated with phylum Firmicutes and Bacteroidetes in the three samples. The wild camels had higher gastrointestinal tract microbial diversity than the domestic one, while the microbial composition of the Lop Nor wild camel shared higher similarity with domestic camel at the genus and family levels than that of the Dunhuang wild camel did. Our results may provide a theoretical basis for assessing their health conditions and may thus be useful for protecting the critically endangered species of C. ferus.  相似文献   

4.
ABSTRACT Populations of Apiosporina morbosa collected from 15 geographic locations in Canada and the United States and three host species, Prunus virginiana, P. pensylvanica, and P. padus, were evaluated using the sequence-related amplified polymorphism (SRAP) technique to determine their genetic diversity and population differentiation. Extensive diversity was detected in the A. morbosa populations, including 134 isolates from Canada and the United States, regardless of the origin of the population. The number of polymorphic loci varied from 6.9 to 82.8% in the geographic populations, and from 41.4 to 79.3% in the populations from four host genotypes based on 58 polymorphic fragments. In all, 44 to 100% of isolates in the geographic populations and 43.6 to 76.2% in populations from four host genotypes represented unique genotypes. Values of heterozygosity (H) varied from 2.8 to 28.3% in the geographic populations and 10.2 to 26.1% in the populations from four host genotypes. In general, the A. morbosa populations sampled from wild chokecherry showed a higher genetic diversity than those populations collected from other host species, whereas the populations isolated from cultivated chokecherry, P. virginiana 'Shubert Select', showed a reduction of genetic diversity compared with populations from wild P. virginiana. Significant population differentiation was found among both the geographic populations (P < 0.05) and populations from different host genotypes (P < 0.02). In the geographic populations, most of populations from cultivated and wild P. virginiana were closely clustered, and no population differentiation was detected except for the populations from Morris, Morden, and Winnipeg, Manitoba, Canada. Furthermore, the populations from P. virginiana in the same geographic locations had higher genetic identity and closer genetic distance to each other compared with those from different locations. Four populations from P. virginiana, P. pensylvanica, and P. padus, were significantly differentiated from each other (P < 0.02), except there was no differentiation between the Shubert Select and wild chokecherry populations (>P> = 0.334). Indirect estimation of gene flow showed that significant restricted gene flow existed between populations from different regions and host species. Gene flow rates (Nm) varied from <1 to 12.5, with higher gene flow rates among population pairs from the same host species (P = 1.000). The analysis of molecular variance revealed that a major genetic variance source came from the genetic variation among isolates within populations regardless of the origin and host genotype of the population. Although some locations had a limited number of isolates, the results of this study clearly showed that the genetic diversity and population differentiation of A. morbosa were closely associated with host genotypes and geographic locations, but mostly with the former.  相似文献   

5.
新疆野扁桃与其近缘种的亲缘关系   总被引:1,自引:0,他引:1  
野扁桃(Amygdalus ledebouriana Schlecht)为野生珍稀濒危植物资源,我国仅分布在新疆。为研究野扁桃与栽培扁桃及其近缘种的亲缘关系,对新疆野扁桃、栽培扁桃、栽培桃和桃属部分物种的叶绿体matK基因进行测序,基于Kimura 双参数模型计算种间遗传距离,并以邻接法(NJ)构建系统发育树。结果表明:野扁桃与蒙古扁桃和榆叶梅的遗传距离较小,与栽培扁桃和桃属物种(桃、山桃和蟠桃)的遗传距离较大;栽培扁桃与山桃、蟠桃和桃的亲缘关系较其与野扁桃、榆叶梅和蒙古扁桃的亲缘关系更近。  相似文献   

6.
通过对锡林郭勒荒漠草地种子植物的组成特征、区系地理成分的分析,结果表明:该区有种子植物55科180属348种,被子植物占优势。科属组成分析表明,区系优势现象较明显,优势科、大属和较大属均以温带分布占优势;属种的地理成分分析表明,温带分布属、种占优势,热带分布的属、种所占比例很小,表明温带属性是该地区植物区系的基本属性,...  相似文献   

7.
宁夏西海固地区农业生态环境面源污染调查研究   总被引:1,自引:0,他引:1  
农业生态环境面源污染控制与保护已成为区域农业和社会协调发展的重大问题。通过调查分析,西海固地区的农业面源污染源主要有化肥、农药、地膜、土壤侵蚀、牲畜禽粪便污染、有污染的灌溉水源与农村生活污水和农村固体废弃物等,并对西海固地区农业面源污染现状及其成因进行了分析。基于农业生态环境面源污染具有污染发生的广泛性、复杂性和治理难度大等特点,提出了防治农业面源污染与保护农业生态环境的对策及建议。  相似文献   

8.
A review on the geographic distribution, vectors and hosts of Bhanja virus (Bunyaviridae) is based on reports about: isolations of the virus; antibody surveys. Bhanja virus has been isolated in 15 countries of Asia, Africa and Europe, and antibodies against it have been detected in 15 additional countries. Vector range includes ticks of the family Ixodidae (subfam. Amblyomminae; not subfam. Ixodinae): 13 species of 6 genera (Haemaphysalis, Dermacentor, Hyalomma, Amblyomma, Rhipicephalus and Boophilus) yielded the virus. Bhanja virus has only rarely been isolated from vertebrates (Atelerix, Xerus, Ovis, Bos; possibly bats), though antibodies have been detected frequently in a wide range of mammals (Ruminantia being the major hosts), in several species of birds (Passeriformes, Galliformes) and even reptiles (Ophisaurus apodus). Natural foci of the Bhanja virus infections are of the boskematic type (sensu Rosicky), associated closely with pastures of domestic ruminants infested by ticks in the regions of tropical, subtropical and partly temperate climatic zones.  相似文献   

9.
A large‐scale survey was carried out to study the host range and genetic diversity of Apple chlorotic leaf spot virus (ACLSV) in various Rosaceae species, with a special emphasis on ornamentals and wild shrubs. Samples were tested by DAS‐ELISA using two different antisera, and RT‐PCR amplification of part of the CP gene. There was generally a poor correlation between the results obtained with the two sets of serological reagents and between serological and molecular detection assays. Using a nested RT‐PCR assay developed here, ACLSV was found to be widespread among cultivated, ornamental and wild species of the Rosaceae. The virus was detected for the first time in plum, wild cherry, Crataegus monogyna, Prunus spinosa and Prunus cerasifera in Greece. Sequences of a part of the CP encoding gene and the 3′ untranslated region from ACLSV isolates originating from various wild species and ornamentals were compared to those of isolates from cultivated hosts, showing similar divergence levels. Further phylogenetic analysis using the sequenced region indicated that the isolates from wild or ornamental hosts were not more closely related to each other than to isolates from cultivated hosts. The possible role of different factors in the spread of ACLSV on cultivated, ornamental and wild species is discussed.  相似文献   

10.
Barley scald fungus, Rhynchosporium commune, belongs to a host‐specialized species complex infecting grasses. Coalescent analyses of several genes indicate that R. commune originated c. 2500 years ago, after the domestication of barley. Phylogeographical analyses identified a diversity hotspot in Scandinavia, indicating an origin in northern Europe. After its emergence, R. commune became distributed globally on infected seeds, eventually invading the Fertile Crescent and infecting wild barley progenitors. Analyses of gene flow identified historical routes of migration out of Scandinavia and indicate a high degree of modern gene flow among South Africa, Australia and New Zealand. About 76% of global species diversity is found within barley fields, with all field populations showing a genetic structure consistent with sexual recombination. High levels of regional gene flow suggest wind‐dispersed ascospores and movement of infected seed. Quantitative traits, including pathogen aggressiveness, thermal sensitivity and fungicide resistance, showed high heritability and high levels of diversity within nine globally representative populations. Field experiments provided evidence for a fitness cost associated with complex virulence and a trade‐off between pathogenic and saprophytic fitness. All findings indicate that global R. commune populations have significant potential to evolve rapidly in response to environmental changes, including deployment of resistant cultivars, fungicide applications and global warming. Specific recommendations to improve management of barley scald include: (i) focus resistance breeding efforts in northern Europe, which offers the best location to screen germplasm and may provide useful sources of scald resistance; (ii) improve seed treatment, certification and quarantine programmes to limit long distance pathogen movement; (iii) manage barley stubble to decrease pathogen population size, limit production of sexual inoculum and reduce the pathogen's evolutionary potential.  相似文献   

11.
"一带一路"倡议在中国西北干旱半干旱区的实施,是否会带来水、大气的污染转移效应引起广泛关注。匮乏的水资源、脆弱的生态环境决定了其不宜引入污染密集型的外商直接投资(FDI)。有别于以往文献从国家、省级层面或分东、中、西地区对FDI的污染转移效应进行研究,本文使用更能体现干旱半干旱区生态、经济差异的城市级数据,运用灰色关联、双重差分方法,研究"一带一路"倡议下,FDI是否对中国西北干旱半干旱区城市水、大气产生污染转移效应。结果显示,"一带一路"倡议实施以来,西北干旱区城市水、大气污染排放与FDI的关联程度下降;且半干旱区远大于干旱区的FDI增幅,并没有导致城市间显著的水、大气污染排放的差异。  相似文献   

12.
Rice production is currently expanding from the south-eastern regions of Australia into northern Australia where indigenous species of wild rice occur widely. A survey of fungal diseases on wild (Oryza australiensis, Oryza spp.) and cultivated rice (Oryza sativa) in North Queensland, Australia, in May 2014 revealed a diverse range of fungal genera species, including important pathogens of cultivated rice. Whilst a single isolate of Magnaporthe oryzae (causal agent of rice blast) was obtained from wild rice, Bipolaris oryzae (causal agent of brown spot) was the predominant pathogen detected under North Queensland conditions. For the first time for Australia, we report Rhizoctonia oryzae-sativae (causal agent of aggregate sheath spot) occurring on wild rice. Other pathogens detected on wild rice included Curvularia lunata, Cochliobolus intermedius, Cochliobolus geniculatus, and Fusarium equiseti present in the majority of wild rice samples. Nearby cultivated rice fields harboured additional pathogens not found in wild rice including Fusarium graminearum, Leptosphaeria spegazzinii and Cochliobolus lunatus, causing scab disease, glume blight and leaf blight, respectively. We also confirmed that Bipolaris oryzae from wild rice can infect cultivated rice. This study highlights the importance of wild rice species as alternative hosts harbouring pathogens of cultivated rice and the likely disease threats to expansion of cultivated rice into the same region(s) where wild rice is endemic.  相似文献   

13.
张掖市甘州城区及外围地下水位上升原因分析   总被引:7,自引:1,他引:6  
采用传统的水均衡方法及环境同位素分析、氟里昂测年等技术,结合地震、地面物探、气象水文及地下水流场分析手段,分析了甘州城区及其外围地下水位上升的原因。结果表明:实施"黑河流域节水灌溉综合治理工程"引起水资源利用分配格局的变化不是引起地下水位大面积上升的原因;水位上升区第四系深层承压水与祁连山基岩裂隙水具有相同的水文地球化学特征和环境同位素特征。其结论:张掖盆地中心地带基底存在与祁连山区相连的北西向深大断裂带一直存在少量,且稳定的地下水越流补给量;自2003年10月山丹、民乐发生大地震以后,使得祁连山山前及盆地内基底断裂活动加剧,同时断裂活动错断了第四系松散层内的隔水层,基底断裂带变为导水通道,加快了祁连山区基岩裂隙水沿着这个通道向上越流补给盆地第四系孔隙水的速度,增大了越流补给量,使盆地地下水补给量大于排泄量,造成地下水位大面积上升。  相似文献   

14.
The European and Mediterranean Plant Protection Organisation (EPPO) aims to prevent the entry and spread of organisms harmful to both cultivated and wild plants. Basing their activities on those of the Convention on Biological Diversity and the International Plant Protection Convention, the EPPO is developing a new concept for invasive alien species and ‘plants as pests’. A pest risk analysis is necessary in most cases to identify which organisms should be regulated and how. In accordance with the International Plant Protection Convention, an EPPO risk assessment standard exists for this purpose which has now been revised to be applicable also to potentially invasive alien plants and assess the effects they pose to the uncultivated environment. In 2003, the EPPO sent a questionnaire to its 44 member states asking for plants which have been intentionally or unintentionally introduced and are considered invasive. The member countries reported hundreds of species, of which 42 were selected for further assessment. This may result in recommendations for regulations and measures against the introduction and spread of all or some of these plants.  相似文献   

15.
黄河上游多民族经济开发区的生态环境建设   总被引:1,自引:1,他引:1  
黄河上游多民族经济开发区是全国国土总体规划纲要中综合开发重点地区之一。本文分析了该地区的生态、环境现状,指出了目前面临的城市大气污染、局部水体污染、水土流失、土地沙化和盐渍化、矿产资源的破坏等生态环境问题。提出了“边发展经济,边治理环境”的生态环境战略和搞好环境规划,合理工业布局;调整能源结构,改善大气环境;治理污染源,净化水环境;发展生态农、林业、保护土地资源,矿产资源开发与环境保护相结合等生态环境治理措施。  相似文献   

16.
A total of 1,366 Rhynchosporium secalis isolates causing scald on barley, rye, and wild barley (Hordeum spontaneum) were assayed for restriction fragment length polymorphism loci, DNA fingerprints, and mating type, to characterize global genetic structure. The isolates originated from 31 field populations on five continents. Hierarchical analysis revealed that more than 70% of the total genetic variation within regions was distributed within a barley field. At the global level, only 58% of the total genetic variation was distributed within fields, while 11% was distributed among fields within regions, and 31% was distributed among regions. A significant correlation was found between genetic and geographic distance. These findings suggest that gene flow is common at the local level while it is low between regions on the same continent, and rare between continents. Analyses of multilocus associations, genotype diversity, and mating type frequencies indicate that sexual recombination is occurring in most of the populations. We found the highest allele richness in Scandinavia followed by Switzerland. This suggests that R. secalis may not have originated at the center of origin of barley, the Fertile Crescent, nor in a secondary center of diversity of barley, Ethiopia.  相似文献   

17.
In most arid and semi-arid regions of the world, domestic livestock and native wildlife share pastures, and their competition for forage and habitat is thought to be a serious conservation issue. Moreover, unmanaged grazing by livestock can cause the population decline in wild ungulates. The diet of an animal species is a determining aspect of its ecological niche, and investigating its diet has been one of the initial steps in basic ecology study of a new species. To get an approximate understanding of the interspecific food relationships of argali(Ovis ammon darwini) between sexes, and sympatric domestic sheep and goats, we compared the diet compositions and diet-overlaps among these herbivores, i.e., male argali, female argali, domestic sheep, and domestic goats in the Mengluoke Mountains of Xinjiang, China by using micro-histological fecal analysis. Female argali, male argali, domestic sheep and domestic goat primarily consumed forbs(43.31%±4.86%), grass(36.02%±9.32%), forbs(41.01%±9.18%), and forbs(36.22%±10.61%), respectively in warm season. All these animals consumed mostly shrubs(female argali: 36.47%±7.56%; male argali: 47.28%±10.75%; domestic sheep: 40.46%±9.56%; and domestic goats: 42.88%±9.34%, respectively) in cold season. The diet-overlaps were relatively high among all species in cold season with values ranging from 0.88 to 0.94. Furthermore, Schoener's index measured between each possible pair of 4 herbivores increased from the warm season to the cold season. The results illustrate that the high degree of diet-overlap of argali and domestic livestock(sheep and goat) may pose a threat to the survival of the argali in cold season. From the viewpoint of rangeland management and conservation of the endangered argali, the numbers of domestic sheep and goats should be limited in cold season to reduce food competition.  相似文献   

18.
Journal of Plant Diseases and Protection - Watermelon mosaic virus (WMV) is one of the most important viruses infecting a wide range of plant species. Population genetic analysis of WMV was...  相似文献   

19.
农药作为重要的生产资料,在保障农业生产的同时,也对农产品和环境构成危害。近年来农药包装废弃物对农业生产和环境生态安全的威胁愈演愈烈。近五年来通州区植物保护站开展多种形式的农药包装废弃物回收工作,旨在探索出最佳农药包装废弃物回收模式,还田园清洁,促进农药包装废弃物回收工作可持续发展。  相似文献   

20.
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