A Review of the Unintentional Release of Feral Genetically Modified Rapeseed into the Environment

Globally, the cultivation area of genetically modified (GM) crops is increasing dramatically. Despite their well-known benefits, they may also pose many risks to agriculture and the environment. Among the various GM crops, GM rapeseed (Brassica napus L.) is widely cultivated, mainly for oil production. At the same time, B. napus possesses a number of characteristics, including the ability to form feral populations and act as small-seeded weeds, and has a high potential for hybridization with other species. In this review, we provide an overview of the commercialization, approval status, and cultivation of GM rapeseed, as well as the status of the feral rapeseed populations. In addition, we highlight the case studies on the unintentional environmental release of GM rapeseed during transportation in several countries. Previous studies suggest that the main reason for the unintentional release is seed spillage during transport/importing of rapeseed in both GM rapeseed-cultivating and -non-cultivating countries. Despite the fact that incidents of unintentional release have been recorded often, there have been no reports of serious detrimental consequences. However, since rapeseed has a high potential for hybridization, the possibilities of gene flow within the genus, especially with B. rapa, are relatively significant, and considering their weedy properties, effective management methods are needed. Hence, we recommend that specific programs be used for the effective monitoring of environmental releases of GM rapeseed as well as management to avoid environmental and agricultural perturbations.

Assessment of Aleutian mink disease virus (AMDV) prevalence in feral American mink in Iceland. Case study of a pending epizootiological concern in Europe

Background Recurring escapes or deliberate releases and subsequent infiltration or establishment of feral populations by individuals from fur farms have been commonly noted since the beginning of fur industry expansion. Once animals have invaded ecosystems adjacent to source farms escapees can change the demography of the feral populations through hybridization, outbreeding depression, competition and spreading of various pathogens which can decimate wild populations. In our study, we aimed to assess spread of Aleutian mink disease virus (AMDV) in the feral population of American mink (Neovison vison) in Iceland. The additional objective was to elucidate whether basic morpho-anatomical parameters (i.e., Fulton’s condition factor or spleen to body weight ratio) might be used as a preliminary indicator of AMDV infection. Methods American mink (n = 164) were captured by professional hunters in 8 regions of Iceland. The detection of AMDV in the spleen of male and female individuals was based on PCR amplification of an NS1 gene fragment. Results We confirmed AMDV presence in 23.8% (n = 39) of collected samples with no significant difference in infection rate between males and females. Additionally, we revealed that the prevalence of virus in the feral population was higher closer to fur farms. However, the countrywide prevalence and direction of AMDV distribution needs to be further investigated. Comparison of condition indices in non-infected and infected animals showed significant deterioration of body and spleen parameters in the latter group. Therefore, the application of basic measurements of the American mink may be used to evaluate the health status of individuals in terms of pathogen infection. Conclusions The study shed a new light on prevalence and distribution of AMDV in the feral population of American mink in Iceland and the results might be successfully applied to develop models to infer dynamics of various pathogens, even those latently transmitted by disease-free animals.

The distribution of American mink (Neovison vison) in Greece

The distribution of the American mink in the wild, originating either from accidental escapes or intentional releases from fur farms, was mapped for the first time in Greece, based on opportunistic data collected from 2010 to 2020. Greece is a key actor in Europe’s fur industry, with most mink farms operating in the northwest. Massive intentional releases by activists took place in the late 2000s, while accidental escapes regularly occur. Most mink were recorded in the Region of Western Macedonia, in NW Greece, within and around the core areas of fur farms, where feral populations became established. Animals were also found further south in the Regions of Thessaly (central Greece) and Central Macedonia (northern Greece). Half of mink records were close to protected areas and almost two-thirds near to watercourses. Many animals were away from the water and on high altitudes, with theoretically less favourable conditions for their survival. We also examine possible directions of further mink range expansion in Greece and neighbouring countries through the river network. Mink invasion progress in Greece is little known, thus, the subject is in urgent need of study, as mink is the alien mammal with the highest impact on the European native fauna.

Escaped oilseed rape: Occurrence in the agricultural landscape and potential pollen-mediated gene flow from crop oilseed rape

To assess the role of feral oilseed rape (OSR) plants as resources for pollinators and avenues for gene flow, we compared occurrence of feral populations in standardized agricultural landscapes, using a landscape ecological approach. The occurrence of feral and volunteer populations was investigated in relation to differences in road length and width, number of OSR fields, and landscape scale. The potential for pollen-mediated gene flow from crop to feral oilseed rape was investigated with fluorescent dye in a field experiment. Moreover, greenhouse estimates of pollen germination rate and pollen tube growth rate were performed to get an indication of siring success in crop and feral plants. Escaped OSR occurred in 14 out of the 16 investigated landscapes, and feral populations were more common alongside large roads than small roads in large-scale landscapes. The number of plants in a habitat ranged from 1-160 individuals, with 1-19 habitats per landscape. In the field experiment with fluorescent dye, no transfer of dye was detected during early flowering in May. At the end of the flowering period in June, transfer of dye was found in 71.4% of the feral plants, showing that significant transfer, most likely by pollinators, occurred from the field to the feral plants. There was no difference in pollen germination rate between crop and feral plants. Pollen tube growth rate was significantly higher in feral oilseed rape than in the crop (P < 0.001). Our results contribute to increased understanding of i) the utilization of feral populations by pollinators in an intensively farmed agricultural landscape, and ii) crop-feral gene flow within OSR.

Ecological Consequences of a Millennium of Introduced Dogs on Madagascar

&lt;p&gt;Introduced predators currently threaten endemic animals on Madagascar through predation, facilitation of human-led hunts, competition, and disease transmission, but the antiquity and past consequences of these introductions are poorly known. We use radiocarbon and stable carbon and nitrogen isotope data from the bone collagen of introduced dogs (Canis familiaris) and endemic fosa (Cryptoprocta spp.) in central and southern Madagascar to test for competition between introduced and endemic predators. Isotopic evidence indicates little overlap in diet between ancient dogs and fosa in these regions but leaves open the possibility that dogs competitively exclude fosa. Radiocarbon dates confirm that dogs have been present on Madagascar for at least a millennium and suggest that they briefly co-occurred with the island&amp;#8217;s extinct megafauna, which included giant lemurs, elephant birds, and pygmy hippopotamuses. Dogs share a mutualism with pastoralists who also at least occasionally hunt, and this is reflected in deposits at several Malagasy paleontological sites that contain dog and livestock bones along with butchered bones of extinct megafauna and extant lemurs. Dogs on Madagascar have had a wide range of diets during the past millennium, but relatively high stable carbon isotope values suggest few individuals relied primarily on forest bushmeat. The absence of distinct dietary differences between dogs from archaeological and paleontological sites may reflect the absence of discrete feral populations. Our data suggest that dogs were part of a suite of animal introductions beginning over a millennium ago that coincided with widespread landscape transformation and megafaunal extinction.&lt;/p&gt;

Frequency, distribution, and ploidy diversity of herbicide-resistant Italian ryegrass (Lolium perenne spp. multiflorum) populations of western Oregon

Italian ryegrass [Lolium perenne L. spp. multiflorum (Lam.) Husnot] is one of the most troublesome weeds worldwide. L. multiflorum is also a grass seed crop cultivated on 50,000 ha in Oregon, where both diploid and tetraploid cultivars are grown. A survey was conducted to understand the distribution, frequency, and susceptibility of L. multiflorum to selected herbicides used to control L. multiflorum. The herbicides selected were clethodim, glufosinate, glyphosate, mesosulfuron-methyl (mesosulfuron), paraquat, pinoxaden, pyroxsulam, quizalofop-P-ethyl (quizolafop), pronamide, flufenacet + metribuzin, and pyroxasulfone. The ploidy levels of the populations were also tested. A total of 150 fields were surveyed between 2017 and 2018, of which 75 (50%) had L. multiflorum present. Herbicide-resistant populations were documented in 88% of the 75 populations collected. The most frequent mechanisms of action were resistance to Acetyl-CoA carboxylase (ACCase), Acetolactate Synthase (ALS), 5-enolpyruvylshikimate-3-phosphate (EPSPs) inhibitors, and combinations thereof. Multiple and cross-resistance, found in 75% of the populations, were the most frequent patterns of resistance. Paraquat-resistant biotypes were confirmed in six orchard crop populations for the first time in Oregon. Herbicide resistance was spatially clustered, with most cases of resistance in the northern part of the surveyed area. ALS and ACCase resistant populations were prevalent in wheat (Triticum aestivum L.) fields. Multiple-resistance was positively correlated with plant density. Tetraploid feral populations were identified, but no cases of herbicide resistance were documented. This is the first survey of herbicide resistance and ploidy diversity in L. multiflorum in western Oregon. Resistant populations were present across the surveyed area, indicating that the problem is widespread.

Molecular genetic polymorphism of American mink populations (Neovison vison) in model fur farms and on the adjacent territories in Belarus

American mink (Neovison vison) is both a problematic invader and an economically valuable fur breed species in Belarus. The increasing scale of mink breeding for fur and the growing impact of this invasive species on the local ecosystems requires sound, novel strategies for managing both farm and wild populations. Containment of wild American mink populations under the effects of possible migration from the fur farms could be especially problematic. With that issue in mind, we have used microsatellite analysis todetermine the genetic polymorphism in two color breeds of farm-bred American mink in the populations of several Belorussian model fur farms, as well as the same characteristics for the feral populations on the territories adjacent to said fur farms. We confirm the presence of effective influx of mink into the wild from fur farms, determined through the means of analyzing microsatellite genotype data of feral and farm populations.

Examining the effect of feralization on craniomandibular morphology in pigs, Sus scrofa (Artiodactyla: Suidae)

Feralization is the process by which domestic animals return to the wild and produce self-sustaining populations. It is often considered as a model in understanding the permanence of morphological changes associated with domestication; however, it is still unclear how much the release of anthropogenic selective pressures affects domestic traits. Here, we assessed the influence of feralization on the domestic morphological traits acquired through selective breeding using craniomandibular differences in shape and size between populations of feral pigs, wild boar and domestic pigs, using landmark-based geometric morphometrics. Our results suggest that numerous cranial and mandibular traits associated with domestication still exist in feral specimens, corroborating that domestication-induced changes in the shape of morphological elements are broadly maintained in feral populations. This is not the case for size variations, however, as the cranium is significantly smaller in feral pigs than in domesticated breeds, which could be due to the selective pressures associated with founding events. Our exploratory study, therefore, underlines the complexity of feral population history, the intricate influence of variations in genetic diversity, and novel selection pressures in the morphology of these groups. Future studies will need to expand the sample to take into account the diversity of morphotypes.