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Summary

Enhancement of the resistance level in plants by rhizobacteria has been proven in several pathosystems. This study investigated the ability of four rhizobacteria strains (Pseudomonas putida BTP1 and Bacillus subtilis Bs2500, Bs2504 and Bs2508) to promote the growth in three barley genotypes and protect them against Cochliobolus sativus. Our results demonstrated that all tested rhizobacteria strains had a protective effect on barley genotypes Arabi Abiad, Banteng and WI2291. However, P. putida BTP1 and B. subtilis Bs2508 strains were the most effective as they reduced disease incidence by 53 and 38% (mean effect), respectively. On the other hand, there were significant differences among the rhizobacteria-treated genotypes on plant growth parameters, such as wet weight, dry weight, plant height and number of leaves. Pseudomonas putida BTP1 strain was the most effective as it significantly increased plant growth by 15-32%. In addition, the susceptible genotypes Arabi Abiad and WI2291 were the most responsive to rhizobacteria. This means that these genotypes have a high potential for increase of their resistance against the pathogen and enhancement of plant growth after the application of rhizobacteria. Consequently, barley seed treatment with the tested rhizobacteria could be considered as an effective biocontrol method against C. sativus.

Summary

This study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.

Summary

The olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae) is the major pest of olives worldwide. The figitid wasp, Aganaspis daci (Hymenoptera: Figitidae), is a larval-prepupal endoparasitoid of fruit fly species, and it was found to successfully parasitize medfly larvae in field-infested figs in Greece. To assess the potential of A. daci as a biological control agent against B. oleae, we studied the effect of olive fruit size on parasitism rates of A. daci on 2nd and 3rd instar larvae of B. oleae, by using fruit of different size (cultivar ‘Chalkidikis’) and wild olive fruit. In addition, we conducted releases of A. daci females in a pilot olive grove in Volos, Magnesia. From July to October, we released 200 A. daci females/0.1 ha/week, followed by olive fruit sampling to estimate olive fruit infestation levels and the parasitism rates of A. daci. Laboratory trials revealed that fruit size and larvae instar were predictors of parasitism success of A. daci, with parasitism rates higher for small-size fruit of the cultivar “Chalkidikis” and the 3rd instar larvae of B. oleae. In field trials, no A. daci adults emerged from the olive fly infested fruit.

Summary

Root-knot nematodes (RKN), Meloidogyne spp., have a wide host range and are common in the Mediterranean area. Cultivated lavender (Lavandula angustifolia) was found naturally infested by M. hapla in Kozani area, the first documented infestation of this crop by RKN in Greece. Oxalis pescaprae, a common winter weed in Crete, was found to be a host of M. javanica under artificial inoculation. This weed acts as a potential winter host of the nematode in fields cultivated with vegetable crops. Two populations of M. ethiopica were found in kiwi and maize in Greece in the past. Recently, populations of M. ethiopica from Europe were re-classified as M. luci, based only on the population isolated from kiwi for Greece. In the current work, the RKN populations originating from kiwi and maize and maintained on tomato, were identified as M. luci. Nematode species identification was determined by electrophoretic analysis of protein extracts obtained from females.

Summary

Phenology and parasitism of the scale insect, Coccus pseudomagnoliarum (Kuwana) (Hemiptera: Coccomorpha: Coccidae), infesting Citrus sinensis (Rutaceae), were studied in Papagou area, in northeastern Athens, from June 2015 to June 2017. Coccus pseudomagnoliarum is a univoltine, viviparous, parthenogenetic species. It overwintered as settled 1st instar nymph on the shoots of the trees. The 2nd instar nymphs appeared between the beginning of April and the end of May, and the mature females were recorded from the beginning of May until the middle of June. The crawlers appeared between the middle of May and the middle of June and the 1st instar nymphs settled on the shoots at the end of May, where they remained during the whole summer period, winter, until the beginning of April next year. Parasitism of the scale was recorded between the beginning of May and the middle of May and reached a maximum rate of 35%. The recorded parasitoid species were Coccophagus shillongensis Hayat and Singh (Hymenoptera: Aphelinidae), Coccophagus spp. and Metaphycus dispar (Mercet) (Hymenoptera: Encyrtidae).

Abstract

Mantle vegetation includes plant communities dominated mostly by shrubs and occurs in habitats where the typical tree layers meet difficulties to evolve. This study was conducted in three areas of Bulgaria – Western Balkan Range, Western Sredna Gora Mt. and the Fore-Balkan. Numerical classification and ordination were performed by PC-ORD and JUICE software packages. Diagnostic species were determined by calculating the Phi-coefficient. Two associations and one plant community of the Berberidion alliance were recognized – Corno-Ligustretum Horvat ex Trinajstić ---amp--- Z. Pavletić 1991, Pruno spinosae-Ligustretum vulgaris Tüxen 1952 and Elytrigia repens-Crataegus monogyna community. The latter considered as a successional stage of shrub encroachment into the grasslands. Its species composition is very close to that of the ass. Corno-Ligustretum. The species composition of ass. Pruno-Ligustretum represents a mixture of species characteristic for dry and mesic grasslands, fringe and forest vegetation. The Crataego-Prunetea class is still poorly studied in Bulgaria and much more data from all regions in the country have to be collected.

Abstract

Echinophora spinosa L., a perennial member of the Apiaceae (Umbelliferae) family is known to be native to southern Europe and Algeria. More recently this taxon was collected from Tabarka (Jendouba-Kroumiria, North-Western of Tunisia) and is reported as a new species for the terrestrial flora of Tunisia. It is described and illustrated and notes on its ecology and phytosociological remarks are provided.

Abstract

Based on hierarchical classification of more than 300 phytosociological relevés of basophilic black and (or) Scots pine communities in the Southern, Eastern and Southeastern Alps we described a new association Rhodothamno chamaecisti-Pinetum sylvestris, into which we classify stands that have until now been discussed in the framework of subassociations Fraxino orni-Pinetum nigrae pinetosum sylvestris, laricetosum deciduae and (partly) caricetosum humilis, and are floristically slightly similar also to certain forms of the association Erico-Pinetum sylvestris. The stands of the new association are for now classified into Natura 2000 habitat type Southeastern-European Pinus sylvestris forests (91R0), within it we propose a special habitat subtype Southeastern-Alpine Scots pine forests, and into a new forest site type Southeastern-Alpine Scots pine forest. At the contact of the Julian and Dinaric Alps we described a new subassociation Genisto januensis-Pinetum sylvestris campanuletosum cespitosae, which comprises also a Natura 2000 species Primula carniolica.

Abstract

The study presents a floristic-sociological classification of the forest vegetation of Kyiv urban area. We identified 18 syntaxa within 7 classes, 7 orders, 8 alliances, and 3 new associations were allocated (Aristolochio clematitis-Populetum nigrae, Galio aparines-Aceretum negundi, Dryopterido carthusianae-Pinetum sylvestris). We analyzed vegetation data using quantitative approaches of ordination and phytoindication. Considering many relevés of transitional nature in the collected data on urban forests, the clustering algorithm of DRSA (Distance-Ranked Sorting Algorithm) was applied to classify vegetation matrix. Large-scale comparative floristic analysis of syntaxa from different regions and countries have been conducted and summarized in differentiating tables.

Abstract

The Central Anatolian vegetation has diverse site conditions and small-scale plant diversity. For this reason, identification of plant communities is important for understanding their ecology and nature conservation. This study aims to contribute the syntaxonomical classification of the Central Anatolian vegetation. The study area is situated among Güzelyurt, Narköy, and Bozköy (Niğde) in the east of Aksaray province of Central Anatolia in Turkey. The vegetation data were collected using the phytosociological method of Braun-Blanquet and classified using TWINSPAN. The ecological characteristics of the units were investigated with Detrended Correspondence Analysis. Three new plant associations were described in the study. The steppe association was included in Onobrychido armenae-Thymetalia leucostomi and Astragalo microcephali-Brometea tomentelli. The forest-steppe association was classified under Quercion anatolicae in Quercetea pubescentis. The riparian association is the first poplar-dominated one described in Turkey and, classified under Alno glutinosae-Populetea albae and its alliance Populion albae.