Xylophilus ampelinus. [Distribution map].

A new distribution map is provided for Xylophilus ampelinus (Panagopoulos) Willems et al. Betaproteobacteria: Burkholderiales: Comamonadaceae. Host: grapevine (Vitis vinifera). Information is given on the geographical distribution in Africa (South Africa), Asia (Japan, Hokkaido, Honshu), Europe (France, Greece, Crete, Italy, Sardinia, Sicily, Russia, Slovenia, Spain).

Characterization and Antimicrobial Activity of a Halophyte from the Asturian Coast (Spain): Limonium binervosum (G.E.Sm.) C.E.Salmon

The work presented herein deals with the characterization and valorization of a halophyte from the cliffs of the Asturian coast: Limonium binervosum (G.E.Sm.) C.E.Salmon (rock sea-lavender). Its biomass and hydromethanolic extracts were studied by elemental and thermal analysis, infrared spectroscopy and gas chromatography–mass spectroscopy. Tetradecanoic acid/esters and 1,2-tetradecanediol were identified in its flower extract, while the leaf extract was rich in linolenic and linoleic acids and their esters, hexadecanoic acid and its esters, and phytol. Both flower and leaf hydromethanolic extracts contained eicosane, sitosterol and tocopherols in significant amounts. With a view to its valorization, the antimicrobial activity of these extracts was investigated against three apple tree and grapevine phytopathogens. Both the hydroalcoholic extracts and their main constituents, alone or in combination with chitosan oligomers (COS), were tested in vitro. A remarkable antibacterial activity was observed for the conjugated complexes of the flower extract with COS, both against Xylophilus ampelinus (MIC = 250 μg·mL−1) and Erwinia amylovora (MIC = 500 μg·mL−1), and complete inhibition of the mycelial growth of Diplodia seriata was found at concentrations <1000 μg·mL−1. In view of these results, this extremophile plant can be put forward as a promising source of bioactive metabolites.

Xylophilus ampelinus (canker of grapevine).

The causative agent of bacterial blight of grapevine, X. ampelinus, is a slow-growing bacterium. It is thought that only European grapevines (Vitis vinifera) are susceptible (Panagopoulos, 1988b). Natural dispersal from infected plants is limited to the vineyard and the immediately surrounding area and is mostly associated with pruning. Dispersal over large distances is expected to occur only associated with host plants, most likely during trading of planting material. It is difficult to control as outbreaks are sporadic and infections are often latent thus hindering detection.

Quarantine and particularly dangerous bacteria, phytoplasmas and viruses that pose a risk to the viticulture in Russian Federation

The Russian Federation imports large quantities of planting and grafting material of grapes, including from countries where dangerous harmful organisms are spread to vineyards. Plant protection specialists in this industry, as well as grape producers, must understand the possible risk associated with the danger of the entry of quarantine disease pathogens into the Russian Federation and the potential damage if infected plant material is imported. Studies have been carried out by the staff of All-Russian Plant Quarantine Center to assess the phytosanitary risk of pests associated with the import of seedlings, stocks and grape cuttings. Based on these studies, the list of pests for the vine that have quarantine status and potentially quarantine status for the Russian Federation, in particular bacterioses, phytoplasmas and viral diseases has been established. This article describes the main diseases that affect grapes and are included in the Unified List of Quarantine Pests of the Eurasian Economic Union, as well as potentially dangerous viral diseases that are not currently included, but planned for inclusion in the Unified List, which pose a serious threat if they penetrate to the territory of the Russian Federation. From quarantine pathogens, grapes are affected by grape bacteriosis (Pierce disease of grapevine) (Xylella fastidiosa Wells et al.), bacterial blight of grapevine (Xylophilus ampelinus (Panagopoulos) Willems et al.), Flavescence dorée of grapevine (Candidatus Phytoplasma vitis), from the planned inclusion grapes are affected by red spotting of grape leaves (Grapevine red blotch-associated virus), marbling of grape leaves (Grapevine vein clearing virus) and discoloration of the leaves of Roditis grape (Grapevine Roditis leaf discoloration-associated virus). The article considers the biological peculiarities of pathogens, ways of their possible penetration and spread on the territory of the cultivation of grape in the Russian Federation, host plants of quarantine and dangerous pests, the main symptoms of diseases on plants, possible vectors, damage caused by quarantine pests in the countries of spreading, diagnostic methods, as well as areas of possible harmfulness for the Russian Federation.

Xenophilus arseniciresistens sp. nov., an arsenite-resistant bacterium isolated from soil

A Gram-reaction-negative, aerobic, motile, rod-shaped, arsenite [As(III)]-resistant bacterium, designated strain YW8T, was isolated from agricultural soil. 16S rRNA gene sequence analysis showed over 97 % sequence similarity to strains of the environmental species Xenophilus azovorans , Xenophilus aerolatus , Simplicispira metamorpha , Variovorax soli , and Xylophilus ampelinus . However, the phylogenetic tree indicated that strain YW8T formed a separate clade from Xenophilus azovorans . DNA–DNA hybridization experiments showed that the DNA–DNA relatedness values between strain YW8T and its closest phylogenetic neighbours were below 24.2–35.5 %, which clearly separated the strain from these closely related species. The major cellular fatty acids of strain YW8T were C16 : 0, C 17 : 0 cyclo, C18 : 1ω7c, and summed feature 3(C16 : 1ω6c and/or C16 : 1ω7c). The genomic DNA G+C content was 69.3 mol%, and the major respiratory quinone was ubiquinone-8. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unknown phospholipids, an unknown polar lipid and phosphatidylserine. The major polyamines were 2-hydroxyputrescine and putrescine. On the basis of morphological, physiological and biochemical characteristics, phylogenetic position, DNA–DNA hybridization and chemotaxonomic data, strain YW8T is considered to represent a novel species of the genus Xenophilus , for which the name Xenophilus arseniciresistens sp. nov. is proposed; the type strain is YW8T ( = CCTCC AB2012103T = KACC 16853T).