In agroecosystems, viruses are well known to influence crop health and some cause phytosanitary and economic problems, but their diversity in non-crop plants and role outside the disease perspective ...is less known. Extensive virome explorations that include both crop and diverse weed plants are therefore needed to better understand roles of viruses in agroecosystems. Such unbiased exploration is available through viromics, which could generate biological and ecological insights from immense high-throughput sequencing (HTS) data.
Here, we implemented HTS-based viromics to explore viral diversity in tomatoes and weeds in farming areas at a nation-wide scale. We detected 125 viruses, including 79 novel species, wherein 65 were found exclusively in weeds. This spanned 21 higher-level plant virus taxa dominated by Potyviridae, Rhabdoviridae, and Tombusviridae, and four non-plant virus families. We detected viruses of non-plant hosts and viroid-like sequences and demonstrated infectivity of a novel tobamovirus in plants of Solanaceae family. Diversities of predominant tomato viruses were variable, in some cases, comparable to that of global isolates of the same species. We phylogenetically classified novel viruses and showed links between a subgroup of phylogenetically related rhabdoviruses to their taxonomically related host plants. Ten classified viruses detected in tomatoes were also detected in weeds, which might indicate possible role of weeds as their reservoirs and that these viruses could be exchanged between the two compartments.
We showed that even in relatively well studied agroecosystems, such as tomato farms, a large part of very diverse plant viromes can still be unknown and is mostly present in understudied non-crop plants. The overlapping presence of viruses in tomatoes and weeds implicate possible presence of virus reservoir and possible exchange between the weed and crop compartments, which may influence weed management decisions. The observed variability and widespread presence of predominant tomato viruses and the infectivity of a novel tobamovirus in solanaceous plants, provided foundation for further investigation of virus disease dynamics and their effect on tomato health. The extensive insights we generated from such in-depth agroecosystem virome exploration will be valuable in anticipating possible emergences of plant virus diseases and would serve as baseline for further post-discovery characterization studies. Video Abstract.
The leafhopper genus Arboridia includes several species that feed on Vitis vinifera and cause leaf chlorosis. We report the first alien Arboridia infestation in Italy in 2021 in an Apulian vineyard. ...To confirm the taxonomic status of the species responsible for crop damage, and reconstruct its demographic history, we barcoded individuals from Apulia together with Arboridia spp. from Crete (Greece), A. adanae from Central Turkey and other specimens of the presumed sister species, A. dalmatina from Dalmatia (Croatia). Molecular phylogenies and barcoding gap analysis identified clades not associated with sampling locations. This result is incongruent with classical specimen assignment and is further supported by morphological analyses, which did not reveal significant differences among the populations. Therefore, we propose A. dalmatina as a junior synonym of A. adanae, which would become the only grapevine-related Arboridia species in the eastern Mediterranean. To further characterise A. adanae evolution, we performed a molecular clock analysis that suggested a radiation during the Pleistocene glaciations. Finally, to assess whether the Apulian individuals carried microorganisms of agricultural relevance, we sequenced their bacterial microbiota using 16S rRNA amplicon sequencing identifying three phytopathogens not generally associated with Arboridia activities as well as Wolbachia in one Apulian haplogroup. We discuss the agricultural implications of this infestation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Flavescence dorée (FD) phytoplasma from 16SrV-C and -D subgroups cause severe damage to grapevines throughout Europe. This phytoplasma is transmitted from grapevine to grapevine by the sap-sucking ...leafhopper
. European black alder and clematis serve as perennial plant reservoirs for 16SrV-C phytoplasma strains, and their host range has recently been extended to hazelnuts. In Slovenia, hazelnut orchards are declining due to 16SrV phytoplasma infections, where large populations of the non-autochthonous leafhopper
have been observed. To better characterise the phytoplasma-induced decline of hazelnut and possible transmission fluxes between these orchards and grapevine, genetic diversity of 16SrV phytoplasmas in grapevine, hazelnut and leafhoppers was monitored from 2017 to 2022. The nucleotide sequence analysis was based on the
gene. The most prevalent
genotype in grapevine in all wine-growing regions of Slovenia was M54, which accounted for 84% of the 176 grapevines tested. Besides M54, other epidemic genotypes with lower frequency were M38 (6%), M51 (3%), M50 (2%) and M122 (1%). M38, M50 and M122 were also detected in infected cultivated hazelnuts and in specimens of
leafhopper caught in declining hazelnut orchards. It suggests that this polyphagous vector could be responsible for phytoplasma infection in hazelnut orchards and possibly for some phytoplasma exchanges between hazelnuts and grapevine. We hereby describe new genotypes: M158 in grapevine as well as four never reported genotypes M159 to M162 in hazelnut. Of these four genotypes in hazelnut, one (M160) was also detected in
. Analysis of additional genes of the new genotypes allowed us to assign them to the VmpA-III cluster, which corresponds to the 16SrV-C strains previously shown to be compatible with
transmission.
Adults and last juvenile stage of a new Dudanus species, Dudanus karra n. sp., are described and illustrated. Some data on ecology and host plant are given. The new species was found in a restricted ...area on both sides of the border between Italy and Slovenia and in Northwestern Italy (Aosta Valley). Figures of D. pallidus Dlabola, 1956 and D. javieri Remane & Della Giustina, 1997, closely related to D. karra, are presented. D. karra differs from these taxa primarily by the shape of the aedeagus. D. pallidus is recorded for the first time from Hungary and Greece. The possibly recent speciation of the Dudanus species in the context of their morphological uniformity is discussed. The endangered condition of Dudanus habitats is highlighted, in particular for D. karra.
A one-year study of the mobility of leafhopper Scaphoideus titanus Ball (ST), vector of Flavescence dorée phytoplasma, was conducted in 2009 and included three Slovenian nurseries in the Primorska ...winegrowing region, as well as two Italian and one Swiss nursery, and was aiming at evaluating the risk of spreading ST with vine propagating material. The presence of ST was monitored by the means of yellow sticky traps that were placed at three distances in the nurseries and the nearby vineyards on three parallel lines (replicates). The traps were equidistantly placed from the nurseries’ and vineyards’ borders in order to determine the possible distance gradient. The monitoring started in the latest nymphal stages (middle of June) and terminated in the first decade of October. Insecticide treatments with deltamethrin (Decis 2.5 EC) were applied in nurseries, according to the instructions for use and recommendations for suppression of ST. On all Slovenian plots in the vineyards, the population level of ST was high (1796 adults in average / vineyard or 18 adults per trap / week), which indicated a great migration potential of the vector towards the nurseries. Catches were very low (54 adults in average / nursery or 0.4 adults / trap / week) on two nurseries’ plots (Lože and Slap), although high numbers of ST adults were caught in the adjacent untreated vineyards. On the Poreče nursery plot, insecticide treatments were not sufficient to avoid high numbers of ST catches (in total 481 adults or 3 adults / trap / week). This could be related to the sub-optimal timing of the first insecticide treatment and/or migration of adults from two nearby untreated vineyards located at a distance of 70 and 150 m. The distance between the nurseries and vineyards did not affect ST catches in the nurseries.
A list of the scale insects (Homoptera: C occoidea) recorded by the authors for the Greek island of C rete is reported. This includes twenty-seven species new to the island The most interesting ...records are Kermes palestiniensis Balachowsky (Kermesidae), only recorded previously from Israel, and Getulaspis bupleuri (Marchal) (Diaspididae), only known previously from North A frica and the Middle E ast. With the present additions, the number of scale insect species recorded on C rete has reached 82. A revised check list of the scales presently known from the island is also provided.
The first occurrence of the East-Palaearctic leafhopper Hishimonus hamatus Kuoh 1976 in Nova Gorica and its surroundings in western Slovenia has been recorded. This is also the first record of this ...species in Europe. Adults and nymphs were found on several ornamental trees: Ligustrum lucidum, L. japonicum, Lagerstroemia indica, Euonymus japonicus, Chamaecyparis lawsoniana and Cupressus sempervirens. Its phytoplasma transmission potential is highlighted.Original Abstract: Zabelezen je prvi pojav skrzatka Hishimonus hamatus Kuoh (Hemiptera: Cicadellidae) v Novi Gorici in okolici. To je tudi prva najdba te vrste v Evropi. Odrasli skrzatki in nimfe so bili nabrani na razlicnih okrasnih rastlinah: Ligustrum lucidum, L. japonicum, Lagerstroemia indica, Euonymus japonicus, Chamaecyparis lawsoniana in Cupressus sempervirens. Izpostavljena je njegova morebitna zmoznost prenasanja fitoplazem.
An overview of alien phytophagous insects and mites that have been introduced or have spread into Slovenia since the mid-19 super(th) century is done. The most comprehensive list of these species ...ever published in Slovenia comprises 169 species, 164 insects and 5 mites. A chronological analysis of introduction and spreading dynamics as well as taxonomic affiliation and origin of these species is shown. Twenty-one species, the occurrence of which has not been officially published yet in Slovenia, are briefly commented.Original Abstract: Napravljen je pregled tujerodnih rastlinojedih zuzelk in prsic, ki so bile vnesene ali so se razsirile v Slovenijo od sredine 19. stoletja dalje. Doslej najbolj celovit seznam teh vrst, napravljen v Sloveniji, obsega 169 vrst, 164 vrst zuzelk in 5 vrst prsic. Prikazana je casovna dinamika vnosa in sirjenja teh vrst ter njihova struktura glede na taksonomsko pripadnost in poreklo. Na kratko je predstavljenih enaindvajset vrst, katerih pojavljanje v Sloveniji doslej se bilo javno objavljeno.
In the Čepovan Valley (Čepovan, hamlet Šulgi), on the northwestern rim of the Banjšice Plateau in the villages of Grudnica (in the Tolmin municipality) and near Sveto to the south of the plateau, we ...found new localities of Thlaspi sylvestre (T. caerulescens), which complement the existing data on the distribution of this species in Slovenia (Srednji Lokovec, Vrata), and surveyed its sites. Thlaspi sylvestre grows on meadows and pastures in the vicinity of human settlements, in hedges, on road banks, on the forest edge and in an open pioneer forest. Its most common companions are Galium mollugo agg. (G. album), Cruciata glabra, Rumex acetosa, Ranunculus acris, Taraxacum sect. Ruderalia and Veronica chamaedrys. Thlaspi sylvestre most frequently occurs in the communities from the class Molinio-Arrhenatheretea. Our findings confirm Tone Wraber’s assumption that it is not indigenous to Slovenia, and was introduced to the Banjšice Plateau as well as to Grudnica and the Čepovan Valley with human assistance (military transport during World War I).
Key words: phytogeography, phytosociology, Thlaspi caerulescens, florula castrensis, Čepovan Valley, Grudnica, Banjšice, Slovenia
Izvleček
V Čepovanski dolini (Čepovan, zaselek Šulgi), na severovzhodnem robu Banjške planote v vasi Grudnica (občina Tolmin) in pri vasi Sveto v južnem delu te planote smo našli nova nahajališča vrste Thlaspi sylvestre (T. caerulescens), ki dopolnjujejo njeno do zdaj znano razširjenost v Sloveniji (Srednji Lokovec, Vrata), in popisali njena rastišča. Raste na travnikih in pašnikih v okolici človeških bivališč, v mejicah, na cestnih brežinah, na gozdnem robu in v svetlem pionirskem gozdu. Njene najbolj pogoste spremljevalke so vrste Galium mollugo agg. (G. album), Cruciata glabra, Rumex acetosa, Ranunculus acris, Taraxacum sect. Ruderalia in Veronica chamaedrys. Najpogosteje raste v združbah iz razreda Molinio-Arrhenatheretea. Potrjujemo domnevo Toneta Wraberja, da ta vrsta v Sloveniji ni samonikla in da se je na Banjšice in tudi v Grudnico in Čepovansko dolino priselila s človekovo pomočjo (vojaškimi transporti med prvo svetovno vojno).
Ključne besede: fitogeografija, fitocenologija, Thlaspi caerulescens, florula castrensis, Čepovanska dolina, Grudnica, Banjšice, Slovenija
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