Investigations of mechanisms of resistance to bipyridyl herbicides in Arctotheca calendula (L.) Levyns

The mechanism of resistance to diquat and paraquat was investigated in a bipyridyl-herbicide-resistant biotype of Arctotheca calendula (L.) Levyns. No differences were observed in the interactions of these herbicides with Photo-system I, the active site, in thylakoids isolated from resistant and susceptible biotypes. Likewise, absorption of herbicide through the cuticle and gross translocation were identical in plants of the two biotypes. Foliar application of either 25 g ha⁻¹ diquat or 200 g ha⁻¹ paraquat rapidly inhibited CO₂-dependent O₂ evolution of leaf segments of the susceptible biotype. O₂ evolution of leaf segments of the resistant biotype was less affected by these treatments. Fluorescence imaging was used to observe visually, as fluorescence quenching, the penetration of herbicide to the active site. These experiments demonstrated that diquat appears at the active site more slowly in the resistant biotype compared to the susceptible biotype. HCO₃-dependent O₂ evolution of thin leaf slices was less inhibited by diquat in the resistant biotype than in the susceptible biotype. The mechanism of resistance to the bipyridyl herbicides in this biotype of A. calendula is not a result of changes at the active site, decreased herbicide absorption or decreased translocation, but appears to be due to reduced herbicide penetration to the active site.     

An updated inventory of the non-native flora of Sardinia (Italy)

We provide an updated inventory of the non-native flora of the Italian island of Sardinia, including accepted names, family, synonyms, biological form, fruit type, introduction pathway and native origin. This inventory was performed by reviewing the available literature and conducting dedicated field surveys across the entire island. The inventory catalogues 931 non-native taxa, including 31 cryptogenic species, 901 species, 14 subspecies, 13 varieties, two forms and one cultivar. We utilised the position on the introduction–invasion continuum concept and meta-population criterion to further label each species. Based on these frameworks, the non-native flora of Sardinia can be divided into 274 casual, 169 naturalised, 19 invasive, 440 exclusively planted and 29 unobserved after 1950. There are 204 archaeophytes and 727 neophytes. The majority of the non-native species (791) were introduced to the island voluntarily, and 140 species were introduced accidentally. The present inventory identifies 72 additional non-native taxa not previously reported in the literature.     

全球外来入侵生物与植物有害生物数据库的比较评价

[目的]为了明确全球生物安全与植物保护领域内数据库建设进展和我国数据库的建设成效,对全球重要的外来入侵生物与植物有害生物数据库进行分类介绍和比较评价研究.[方法]根据数据库收录物种的地理范围、类群及数据库特色功能,对数据库进行分类.对重要数据库的主要功能进行简要介绍,设立多指标评价体系将我国数据库与国际优质数据库进行比...     

浅析潜在外来入侵物种——苹浅褐卷蛾

苹浅褐卷蛾Epiphyas postvittana原产澳大利亚,是澳大利亚西南部、新西兰、英国及美国多种经济作物的重要害虫,目前尚未在全球范围广泛分布。由于其地理分布范围窄、寄主植物广泛、形态鉴定困难、能够对农作物造成较大的经济危害以及具有遗传多样性等特点,目前已被多数国家列为检疫对象并提出严格的检疫要求。而2007年该虫在美国加州地区的定殖使得研究人员对该虫能够造成的危害程度引起了再次的关注。在我国,该虫也被列为对外检疫对象,但是相关报道相对较少。作为检疫性害虫,对其相关信息的综合掌握是进一步进行有害生物风险分析的基础和保障。本文详细描述了苹浅褐卷蛾的地理分布、寄主范围、发生为害与环境条件的相互关系等,以期为该虫进行进一步风险分析及对其的检疫措施的制定和实施提供重要的信息与依据。     

The silent invasion of Eichhornia crassipes (Mart.) Solms. in Italy

This article provides general information and original data on the period of first introduction in Europe (1823–1825) and in Italy (first half of the 19th century), and on the current distribution and impacts in Italy of the invasive macrophyte Eichhornia crassipes. Two main pathways are responsible for the presence of this species in Italy: (i) introduction as an ornamental and (ii) research and use for phytoremediation. After a time lag of more than 100 years, E. crassipes has recently started invading the Italian freshwaters. A specific action plan for this species is required, including local eradication and awareness campaigns. Furthermore, regulations in the trade sector of invasive aquatic plant species need to be introduced and the possibilities for biological or integrated control evaluated.     

Molecular identification and expression analysis of magnetic receptor in Spodoptera frugiperda (Lepidoptera: Noctuidae), an invasive species in China

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), has emerged as a highly invasive pest globally in the past decade due to its remarkable migratory capabilities. Magnetic receptors play an important role in the migration and navigation of the animal, but little is known about the molecular mechanism of the magnetic receptors of S. frugiperda (SfMagR). In this study, we successfully cloned the cDNA encoding SfMagR, which has a 396 bp of open reading frame (ORF) encoding 132 amino acids. Phylogenetic analysis revealed a high conservation of magnetic receptors among various animal species, notably demonstrating a 98.4% sequence identity between S. frugiperda and Spodoptera litura, and a 70.3% identity with Homo sapiens, a vertebrate species. Expression analysis conducted across different developmental stages demonstrated SfMagR expression in the egg, larval, and pupal stages of the moth, but exhibited predominate expression in the adult stage, particularly in male adults. Moreover, the tissue expression profile indicated that SfMagR expression primarily occurred within the thorax of the moth, specifically in the thorax excluding the legs and wings. These findings not only provide fundamental data and a molecular foundation for future investigations into the function of SfMagR, but also offer valuable insights for the future management of invasive species.     

成都市外来入侵植物种类特征及区系分析

【目的】全面掌握成都市外来入侵植物的种类特征、起源、区系成分和危害情况等特征,为相关部门制定管理策略和及早采取应对措施提供依据。【方法】以实地调查为主,结合标本及文献研究的方式获得成都市外来入侵植物的种类和分布信息,根据其在野外的生长和分布状况进行评估及划分危害等级,并进行植物区系分析。【结果】成都市现有外来入侵植物158种(亚种、变种),隶属42个科110个属,其中种类最多的3个科分别是菊科(36种)、豆科(17种)及禾本科(13种),合计占比41.77%;种类最多的属是苋属(8种),占比5.06%。原产地分析结果表明,有101种来自美洲地区,占比63.92%。从危害等级分析来看,其中19种为恶性入侵种(1级),32种为严重入侵种(2级),20种为局部入侵种(3级),41种为一般入侵种(4级)以及46种为有待观察种(5级)。植物区系分析结果显示,成都市外来入侵植物属的分布类型主要为泛热带分布、热带亚洲及热带美洲间断分布和世界分布。【结论】成都市地区的外来入侵植物种类明显增多,扩散趋势已加剧。根据上述入侵现状,本文对成都市地区防范外来植物入侵提出了以下4点防控建议:建立外来入侵植物风险评价体系,开展防控和利用技术研发,谨慎引种以及加强科普教育。     

云南省外来入侵植物的区系成分及多样性分析

【目的】弄清云南省外来入侵植物的区系成分及多样性成因,为减少外来入侵植物对云南省生物多样性的影响提供理论依据。【方法】在已知云南省外来入侵植物种类组成的基础上,对其科、属、种的分布区类型进行了分析,并从生态指标(种子植物数、气候类型数、地表水总量、年均最高温)及社会经济指标(10年总进口额,10年总入境游客数) 2方面,将云南省与其他入侵植物多样性最高的9个省市进行比较,以探讨外来入侵植物多样性的成因。【结果】在区系组成上,云南省外来入侵植物的热带成分占绝对优势,其比例在科、属、种水平上分别为50.85%、63.16%和63.39%。入侵种所在科、属,常广域分布,但入侵种原产地分布范围却不大,并倾向于集中在某些特定区域(如热带美洲、狭义地中海区)。入侵植物所在科的入侵种数与该科包含的世界种数存在显著性正相关。省市级行政区域内入侵植物种数与该省市国际贸易额、入境游客数等指标没有相关性,而与各省市的种子植物数、气候类型数存在显著性关系,与地表水总量和年均温度存在一定的关系。【结论】云南省的自然生境适宜外来入侵植物的生存和扩散。需要对具有热带性质,所在分类单元为大科、大属,且地理分布距离与云...     

Streamlining 'search and destroy': cost-effective surveillance for invasive species management

Invasive species surveillance has typically been targeted to where the species is most likely to occur. However, spatially varying environmental characteristics and land uses may affect more than just the probability of occurrence. Biodiversity or economic value, and the ease of detection and control are also likely to vary. We incorporate these factors into a detection and treatment model of a low-density invader to determine the surveillance strategy that minimizes expected management costs. Sites with a high probability of invader occurrence and great benefits associated with detection warrant intensive surveillance; however, the optimum investment is a nonlinear function of these factors. Environments where the invader is relatively easy to detect are prioritized for surveillance, although only a moderate investment is necessary to ensure a high probability of detection. Intensive surveillance effort may be allocated to other sites if the probability of occurrence, budget and/or expected benefits is sufficiently high.     

Seedling traits, plasticity and local differentiation as strategies of invasive species of Impatiens in central Europe

Background and Aims

Invasiveness of some alien plants is associated with their traits, plastic responses to environmental conditions and interpopulation differentiation. To obtain insights into the role of these processes in contributing to variation in performance, we compared congeneric species of Impatiens (Balsaminaceae) with different origin and invasion status that occur in central Europe.

Methods

Native I. noli-tangere and three alien species (highly invasive I. glandulifera, less invasive I. parviflora and potentially invasive I. capensis) were studied and their responses to simulated canopy shading and different nutrient and moisture levels were determined in terms of survival and seedling traits.

Key Results and Conclusions

Impatiens glandulifera produced high biomass in all the treatments and the control, exhibiting the ‘Jack-and-master’ strategy that makes it a strong competitor from germination onwards. The results suggest that plasticity and differentiation occurred in all the species tested and that along the continuum from plasticity to differentiation, the species at the plasticity end is the better invader. The most invasive species I. glandulifera appears to be highly plastic, whereas the other two less invasive species, I. parviflora and I. capensis, exhibited lower plasticity but rather strong population differentiation. The invasive Impatiens species were taller and exhibited higher plasticity and differentiation than native I. noli-tangere. This suggests that even within one genus, the relative importance of the phenomena contributing to invasiveness appears to be species''specific.     

DNA barcoding as a tool for early warning and monitoring alien duckweeds (Lemna sp.pl.): the case of Central Italy

Aquatic habitats are vulnerable to the invasion of alien species, so early warning protocols are necessary for eradication. The presence in Italy of two alien duckweeds in freshwaters has been documented: Lemna minuta, that showed high invasivity, and L. valdiviana, still confined to south Lazio. These two species may be mistaken for each other and for the domestic L. minor and L. gibba due to morphological variation. Here, we assess the applicability of DNA barcoding as a complement to morphological analysis for monitoring the spread of alien Lemna. We chose two chloroplast genome sequences for their ability to discriminate all Lemna species: the 5’ intron of the trnK gene and the matK gene. Among 48 samples of Lemna collected at 20 sites in Central Italy, 20 were identified as L. minor, 19 as L. minuta, five as L. trisulca and four as L. gibba. L. minuta was present at most sampling sites; in particular, at six locations of Lake Trasimeno, eight L. minuta samples were found. We demonstrate that DNA sequence analyses with cost-effective barcoding techniques can effectively support expert efforts in species determination for an early alert system of invasive Lemna species.     

基于快速普查方法的深圳植被优势种特征研究

植被普查是了解城市地表植被群落特征最常见的方法,也是进一步进行城市生态学、植物学等研究的方法基础。基于植被调查的不同目的、不同尺度、不同地貌,调查人员所选择的方法也各有差异。此次调查旨在对深圳陆域尺度的优势种特征进行研究,利用高分辨率遥感卫星图片与地面实地调查相结合的方法对深圳陆域植被开展了快速普查,结果显示：（1）深圳陆域共有优势植物182科、858属、1443种,其中被子植物占主要地位,占优势植物总种数的94.66%;（2）从优势种子植物科的地理分布来看,深圳陆域优势种子植物科归属于14个分布区,植物地理成分较为复杂,热带区系属性非常明显;（3）划分出非邻近的纹理异质性群丛斑块83834个,归为741类群系,12个植被型,南亚热带常绿阔叶林、南亚热带草丛、南亚热带灌丛占绝对优势;（4）经统计,郊区群系类型较城区更为丰富,郊区608类群系,城区569类群系,其中,共有群系437类,城-郊各自优势植物科、属、种数量差异不明显;（5）对比《中国外来入侵植物名录》和相关学者的学术论文,筛选出深圳外来入侵植物62科、200属、258种,主要集中在豆科、菊科、禾本科等科。根据本次植被快速普查过程和结果给出城市植被管理和改善植被普查方法的建议,旨为今后的城市政策制定和规划实施提供科学依据。另外为了验证此次调查方法的科学性和调查结果的正确性,将本文结果与采用传统长周期方法的两支高校调查队伍的调研结果进行了比对,本次结果包含高校队伍调查结果优势种数量的88.5%,体现了本方法在优势植物物种普查中的有效性。     

湛江市外来植物入侵状况

[目的]了解湛江市外来入侵植物的种类特征、生活型、起源和危害情况等,对制定预防和控制管理措施提供参考。[方法]以野外调查为主,结合文献资料、网络资源以及标本数据,确定湛江市外来入侵植物的种类、生活型、原产地、引入途径,并进行评估及划分危害等级。[结果]湛江市现有外来入侵植物共112种(含变种),隶属于37科89属,其中,菊科(21种)、禾本科(13种)和豆科(13种)为种类较多的3个科,三者合计占湛江市外来入侵植物总种数的41.96%。湛江市外来入侵植物中以草本植物居多(98种),占入侵植物总数的87.50%。入侵植物主要来源于美洲,共82种,占总种数的73.21%;且55.36%(62种)的入侵植物为有意引入。从危害等级看,外来入侵植物中恶性入侵种(1级)23种,严重入侵种(2级)35种,局部入侵种(3级)21种,一般入侵种(4级)15种,有待观察种(5级)18种。[结论]湛江市的外来入侵植物种类繁多,这与湛江独特的地理位置以及日趋频繁的人类活动息息相关,应当加强监管与防范,及时对外来物种进行治理。     

Invasive European frogbit (Hydrocharis morsus-ranae L.) in North America: an updated review 2003-16

Aims European frogbit (Hydrocharis morsus-ranae L.) is an aquatic plant originating from Europe that has emerged as an invasive species, spreading in the USA and Canada since it was first brought to North America in 1932. It can now be found in many water bodies, from small ponds and long rivers to large lakes such as Lake Ontario and Lake Erie. The continuous spread of this species indicates its success as an invasive species despite legislative attempts to limit its distribution. Catling et al. (Catling PM, Miltrow G, Haber E, et al. (2003) The biology of Canadian weeds. 124. Hydrocharis morsus-ranae L. Can J Plant Sci 83:1001–16) wrote a thorough review about this invasive species in North America. Our review aims for a compilation of the most recent available data and recent studies on H. morsus-ranae L. and focuses primarily on its environmental uses, ecological impacts and management. The purpose of this review is to offer an organized and updated report on European frogbit that can be used towards future studies with the goal of eradicating this invasive species and providing insights on management of other invasive plants.Important findings Our findings reveal that European forgbit's ecological effects on other species and the invaded environment were shown to be less harmful than previously feared. European frogbit had negative impacts on native plants and reduced dissolved oxygen concentration. However, water chemistry, phytoplankton and zooplankton communities were actually not affected by European frogbit. For fungi, bacteria and macroinvertebrates, studies have showed complex and sometimes conflicting results. We also specifically discussed the new method to control this species using shading and the more recent studies on biological control. Shading with a shade cloth has been shown to effectively remove European frogbit and had minor environmental effects. However, using biological control to combat the spread of the invasive frogbit seems not as successful as we wished.     

Naturalization of exotic plant species in north‐eastern North America: trends and detection capacity

Aim To reconstruct historical naturalization trends of exotic vascular plants in Quebec and Massachusetts, two regions that experienced fluctuations in their herbarium specimen collection efforts. We hypothesized that the observed trends are linked to the collection effort and that they differ according to the motive for plant introduction. Methods A checklist of naturalized exotic plant taxa for Quebec, including oldest proof of naturalization and motive for introduction, was built from herbaria, journals, dissertations, theses, bulletins, websites and unpublished records. For Massachusetts, we used the checklist of Sorrie (2005; Rhodora, 107 , 284–329). The collection effort was estimated from a pool of species with specimens from the five largest Quebec herbaria and from the Harvard University Herbarium. Results Naturalization trends of exotic plants in Quebec are similar to those observed in Massachusetts. A large part of the plants naturalized in the 17th, 18th or 19th centuries, with very little naturalization during the last 30–90 years. In general, there is a significant statistical link between herbarium specimen collection effort and the discovery of new naturalized plant taxa. Very few utilitarian plants naturalized in either region during the 20th century. In Quebec, a high number of ornamental plants naturalized during the last 100 years. Main conclusions The link between herbarium specimen collection effort and the discovery of new naturalized plants is real, although not as straightforward as it seems. Our analysis suggests that at least part of the decline in the number of new naturalized exotic plants observed in Quebec and Massachusetts during the last 30–90 years is a direct consequence of the low interest for traditional floristic studies. However, the possibility of a real decline cannot be ruled out. We nevertheless provide here one of the first pieces of evidence of the potential consequences of the decline of local plant collection for environmental management and especially for early detection systems of new invaders.     

中国外来入侵生物的危害与管理对策

本文探讨了外来入侵生物的概念及其在我国的危害状况,入侵原因,提出了外来入侵生物 预防及管理对策,随着国际贸易往来和旅游业的发展,生物入侵在我国不断加剧,正在成为威胁我国生物多样性与生态环境的重要因素之一,外来入侵种的生态代价是造成本地物种多样性不可弥补的消失以及物种的灭绝,其经济代价是农林牧渔业产量与质量的惨重损失与高额的防治费用,生物入侵在我国大部分是由于人为因素引起的,这些因素包括：缺乏对引进种的利益与风险进行评估,淡薄的生态意识与不顾生态后果的经济利益驱使下的盲目引进,缺乏严格的科学监管体系或监管不力,缺乏全面检疫的体系与机制。外来入侵生物的综合性与系统性研究已成为当今我国生态环境保护、农业生产和经济可持续发展的重大研究领域,我国对外来入侵生物的预防与管理应着重于国家能力、研究能力,监测与管理能力三大体系的建设上,根据我国国情和目前的紧急现状应制定出优先行动计划,对特定外来种的入侵生物学基础研究,特定生态系统或地理区域入侵种现状及影响的关键评估研究,特定外来入侵生物对生态环境影响的风险评估体系及经济损失的模式研究、发展控制外来有害生物的环保型技术与方法研究,外来生物受控制后生态系统的恢复与栖息生境的复原技术与方法等,无意 目前亟待研究的课题。     

Optimal surveillance and eradication of invasive species in heterogeneous landscapes

Cost-effective surveillance strategies are needed for efficient responses to biological invasions and must account for the trade-offs between surveillance effort and management costs. Less surveillance may allow greater population growth and spread prior to detection, thereby increasing the costs of damages and control. In addition, surveillance strategies are usually applied in environments under continual invasion pressure where the number, size and location of established populations are unknown prior to detection. We develop a novel modeling framework that accounts for these features of the decision and invasion environment and determines the long term sampling effort that minimises the total expected costs of new invasions. The optimal solution depends on population establishment and growth rates, sample sensitivity, and sample, eradication, and damage costs. We demonstrate how to optimise surveillance systems under budgetary constraints and find that accounting for spatial heterogeneity in sampling costs and establishment rates can greatly reduce management costs.     

Spatial patterns of species diversity in sand dune plant communities in Yucatan,Mexico: importance of invasive species for species dominance patterns

Background: Coastal ecosystems in Mexico remain understudied in spite of their ecological, economic and conservation value and are being impacted by human activities along the coast. Knowledge on spatial patterns of plant species distribution that helps preserve these fragile ecosystems is crucial.

Aims: We evaluated differences in species richness, species diversity and species dominance patterns in 16 plant communities as well as the degree to which differences were driven by climatic conditions in sandy dunes in Yucatán. We evaluated the importance of invasive species in mediating patterns of species diversity and species dominance patterns.

Results: We found wide variation in plant species richness, species diversity and species dominance patterns among communities that stems from broad climatic differences along dune systems. Invasive plants represent almost one-third of total species richness and seem to be drastically changing the species dominance patterns in these communities.

Conclusions: Regional climatic differences along the Yucatán north coast seems to be a major driver of plant diversity and species composition. Our findings suggest that invasive plants have successfully colonised and spread along the coast over the past 30 years. Even though invasive species do not alter spatial patterns of species diversity, they are becoming more dominant with potential detrimental consequences for native plants.     

Prunus serotina in Italy: a challenging candidate for the national list of priority invasive alien species

Abstract

In accordance with the European regulation on Invasive Alien Species (IAS), the black cherry tree (Prunus serotina Ehrh.) has recently been indicated as one of the 96 species proposed for the development of the national list of priority invasive alien species in Italy. The species, native to North America, is recognised as one of the most harmful IAS in Europe, given its high spread potential and the associated ecological and economic impacts reported in its alien range. Although P. serotina is recognised as a pest within the EU, plants are still available on the market, confirming intentional introduction as a current potential pathway for this species arrival into new areas. Since a comprehensive overview of the main features characterizing the invasive potential of this species is still lacking, we aim to underpin the high priority status of P. serotina as a IAS of main concern in Italy by outlining the main biological features, pathways and impacts of the black cherry in its secondary range. Management measures to be potentially included in specific action plans are also summarised.