Utvrđivanje rezistentnosti Myzus persicae (Sulzer) molekularnim metodama

In two years of investigating resistance of the peach-potato aphid Myzus persicae (Sulzer) by molecular methods, several types of resistance were established in the majority of individuals from peach and tobacco in Serbia and Montenegro. Most of the tested individuals had the FE4 gene, which encodes production of FE4 esterase. The gene responsible for kdr (knock-down resistance) was found in the majority of individuals, but in the heterozygous state, while resistance based on formation of modified acetlycholinesterase (MACE) was least represented. Also, tests showed aphids from tobacco to be more sensitive to insecticide action than aphids from peach. Three tests were used in these investiga­tions, e.g., the PCR - esterase, PCR - kdr, and RFLP - PCR tests, each for a single type of resistance.U dvogodišnjim istraživanjima rezistentnosti zelene breskvine vaši, Myzus persicae (Sulzer) molekularnim metodama, ustanovljeno je da je kod većine testiranih jedinki sa breskve i duvana u Srbiji i Crnoj Gori, utvrđen neki od tipova rezistentnosti. Većina testiranih jedinki imala je FE4 gen koji kodira produkciju FE4 karboksilesteraze. Gen odgovoran za kdr (knock-down rezistentnost) nađen je kod većine jedinki, ali u heterozigotnom stanju dok je rezistentnost koja se zasniva na stvaranju modifikovane acetilholinesteraze (MACE) najmanje zastupljena. Takođe, testovi su pokazali da su vaši sa duvana osetljivije na dejstvo insekticida od vašiju sa breskve. U ovim istraživanjima korišćena su tri testa: PCR-esteraza test, PCR-kdr i RFLP-PCR, svaki za po jedan tip rezistentnosti

Tracking the global dispersal of a cosmopolitan insect pest, the peach potato aphid

<p>Abstract</p> <p>Background</p> <p>Global commerce and human transportation are responsible for the range expansion of various insect pests such as the plant sucking aphids. High resolution DNA markers provide the opportunity to examine the genetic structure of aphid populations, identify aphid genotypes and infer their evolutionary history and routes of expansion which is of value in developing management strategies. One of the most widespread aphid species is the peach-potato aphid <it>Myzus persicae</it>, which is considered as a serious pest on various crops in many parts of the world. The present study examined the genetic variation of this aphid at a world scale and then related this to distribution patterns. In particular, 197 aphid parthenogenetic lineages from around the world were analysed with six microsatellite loci.</p> <p>Results</p> <p>Bayesian clustering and admixture analysis split the aphid genotypes into three genetic clusters: European <it>M. persicae persicae</it>, New Zealand <it>M. persicae persicae </it>and Global <it>M. persicae nicotianae</it>. This partition was supported by <it>F</it>_STand genetic distance analyses. The results showed two further points, a possible connection between genotypes found in the UK and New Zealand and globalization of <it>nicotianae </it>associated with colonisation of regions where tobacco is not cultivated. In addition, we report the presence of geographically widespread clones and for the first time the presence of a <it>nicotianae </it>genotype in the Old and New World. Lastly, heterozygote deficiency was detected in some sexual and asexual populations.</p> <p>Conclusion</p> <p>The study revealed important genetic variation among the aphid populations we examined and this was partitioned according to region and host-plant. Clonal selection and gene flow between sexual and asexual lineages are important factors shaping the genetic structure of the aphid populations. In addition, the results reflected the globalization of two subspecies of <it>M. persicae </it>with successful clones being spread at various scales throughout the world. A subspecies appears to result from direct selection on tobacco plants. This information highlights the ultimate ability of a polyphagous aphid species to generate and maintain ecologically successful gene combinations through clonal propagation and the role of human transportation and global commerce for expanding their range.</p

Occurrence of target-site resistance to neonicotinoids in the aphid Myzus persicae in Tunisia, and its status on different host plants

This is the peer reviewed version of the following article: Kamel Charaabi, Sonia Boukhris-bouhachem, Mohamed Makni, and Ian Denholm, ‘Occurrence of target‐site resistance to neonicotinoids in the aphid Myzus persicae in Tunisia, and its status on different host plants’, Pest Management Science, Vol. 74(6): 1297-1301, June 2018, which has been published in final form athttps://doi.org/10.1002/ps.4833 Under embargo until 19 December 2018. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.BACKGROUND: The R81T mutation conferring target-site resistance to neonicotinoid insecticides in Myzus persicae was first detected in France and has since spread across much of southern Europe. In response to recent claims of control failure with neonicotinoids in Tunisia, we have used a molecular assay to investigate the presence and distribution of this target-site mutation in samples collected from six locations and six crops attacked by M. persicae. RESULTS: The resistance allele containing R81T was present at substantial frequencies (32–55%) in aphids collected between 2014 and 2016 from northern Tunisia but was much rarer further south. It occurred in aphids collected from the aphid's primary host (peach) and four secondary crop hosts (potato, pepper, tomato and melon). Its absence in aphids from tobacco highlights complexities in the systematics of M. persicae that require further investigation. CONCLUSION: This first report of R81T from North Africa reflects a continuing expansion of its range around the Mediterranean Basin, although it remains unrecorded elsewhere in the world. Loss of efficacy of neonicotinoids presents a serious threat to the sustainability of aphid control.Peer reviewe

Fluid geochemistry investigations on the volcanic system of methana

An extensive geochemical survey on the fluids released by the volcanic/geothermal system of Methana was undertaken. Characterization of the gases was made on the basis of the chemical and isotopic (He and C) analysis of 14 samples. CO2 soil gas concentration and fluxes were measured on the whole peninsula at more than 100 sampling sites. 31 samples of thermal and cold groundwaters were also sampled and analysed to characterize the geochemistry of aquifers. Anomalies referable to the geothermal system, besides at known thermal manifesta-tions, were also recognized at some anomalous degassing soil site and in some cold groundwater. These anomalies were always spatially correlated to the main active tectonic system of the area. The total CO2 output of the volcanic system has been preliminary estimated in about 0.2 kg s-1. Although this value is low compared to other volcanic systems, anomalous CO2 degassing at Methana may pose gas hazard problems. Such volcanic risk, although restricted to limited areas, cannot be neglected and further studies have to be undertaken for its better assessmen

Smoking and Pulmonary Fibrosis: Novel Insights

The relationship between smoking and pulmonary fibrosis is under debate and intense investigation. The aim of this paper is to review the existing literature and identify further areas of research interest. Recently the negative influence of cigarette smoking on IPF outcome was highlighted, as non-smokers exhibit a better survival than ex-smokers and combined current- and ex-smokers. In patients with non-specific interstitial pneumonia (NSIP), a high prevalence of emphysema was recently demonstrated, providing an indirect support for a smoking pathogenetic hypothesis in NSIP. The coexistence of pulmonary fibrosis and emphysema has been extensively described in a syndrome termed combined pulmonary fibrosis and emphysema (CPFE). Connective tissue disorders (CTDs) are a group of autoimmune diseases which affect the lung, as one of the most common and severe manifestations. However, the relationship between smoking and autoimmune disorders is still conflicting. Rheumatoid arthritis results from the interaction between genetic and environmental factors, while the best established environmental factor is tobacco smoking. Smoking has also a negative impact on the response of the RA patients to treatment. The aforementioned smoking-related implications give rise to further research questions and certainly provide one more important reason for physicians to advocate smoking cessation and smoke-free environment

New records of aphid species (Hemiptera: Aphididae) in Greece

Τις τελευταίες δυο δεκαετίες έχουν δημοσιευθεί αρκετές εργασίες σχετικές με την αφιδοπανίδα της Ελλάδας. Ωστόσο, ο αριθμός των καταγεγραμμένων ειδών αφίδων είναι αρκετά μικρότερος από άλλες Ευρωπαϊκές χώρες, συμπεριλαμβανομένων αυτών στη λεκάνη της Μεσογείου. Στην παρούσα εργασία συλλέξαμε δείγματα αφίδων από διάφορους ξενιστές και περιοχές της νότιας, κεντρικής και βόρειας Ελλάδας. Συνολικά συλλέχθηκαν 128 είδη αφίδων, που ανήκουν σε 55 γένη και έξι υποοικογένειες, από 200 είδη φυτών-ξενιστών. Τα περισσότερα είδη αφίδων ανήκαν στην υποοικογένεια Aphidinae (ειδικά στις φυλές Macrosiphini και Aphidini). Δεκαοκτώ από τα συλλεχθέντα είδη είναι νέες αναφορές για την Ελλάδα. Τα αποτελέσματα της παρούσας εργασίας αυξάνουν τη γνώση μας σχετικά με την αφιδοπανίδα της Ελλάδας και δείχνουν ότι ο αριθμός των καταγεγραμμένων ειδών στην Ελλάδα μπορεί να αυξηθεί σημαντικά αν πραγματοποιηθούν επιπλέον σχετικές μελέτες. Several papers have been published on aphid fauna in Greece during the last two decades, but the number of recorded species is still low compared to other European countries, including some from the Mediterranean basin. In this context, we collected aphids from various host-plants and regions in southern, central and northern Greece characterized by diverse flora, climatic conditions and ecological habitats. In total, 128 aphid species belonging to 55 genera and six subfamilies were collected on 200 host-species. Most of the species dominated the subfamily Aphidinae (especially tribes Macrosiphini and Aphidini). Among the species collected, 18 were new records in Greece. The present work improves our knowledge regarding the aphid fauna of Greece and suggests that the number of recorded species could increase further if additional studies were undertaken