Response of aphid predators to synthetic herbivore induced plant volatiles in an apple orchard.

The indirect defence compounds termed herbivore induced plant volatiles (HIPVs), which are used to attract beneficial fauna, are one of the most effective biological control tools for the aggregation of natural enemies of key pests. The aim of this study was to test the attraction of three aphid predators of the Chrysopidae, Coccinellidae and Syrphidae families using synthetic formulations of four main HIPVs [methyl salicylate (MeSa), benzaldehyde (B), linalool (L) and farnesene (F)] alone and in binary combinations (MeSa + B; MeSa + F; MeSa + L; F + B; B + L; F + L) in an apple orchard in the Bursa province of Turkey. This study was the first demonstration of the attraction of these aphid predators to single and binary combinations of synthetic HIPVs in an apple orchard. A larger number of coccinellids were captured using single treatments of both B and F than with other HIPV combinations. Furthermore, the chrysopid individuals studied were significantly attracted to traps baited with single HIPVs. In addition, the binary combination of MeSa + L significantly attracted more Syrphids than in both single treatments and control traps. Thus, some of the HIPV’s tested were found to have potential value for the congregation of aphid predators in apple orchard

Bacteriophage-mediated control of phytopathogenic xanthomonads: A promising green solution for the future

Xanthomonads, members of the family Xanthomonadaceae, are economically important plant pathogenic bacteria responsible for infections of over 400 plant species. Bacteriophage-based biopesticides can provide an environmentally friendly, effective solution to control these bacteria. Bacteriophage-based biocontrol has important advantages over chemical pesticides, and treatment with these biopesticides is a minor intervention into the microflora. However, bacteriophages’ agricultural application has limitations rooted in these viruses’ biological properties as active sub-stances. These disadvantageous features, together with the complicated registration process of bacteriophage-based biopesticides, means that there are few products available on the market. This review summarizes our knowledge of the Xanthomonas-host plant and bacteriophage-host bacterium interaction’s possible influence on bacteriophage-based biocontrol strategies and provides examples of greenhouse and field trials and products readily available in the EU and the USA. It also details the most important advantages and limitations of the agricultural application of bacteriophages. This paper also investigates the legal background and industrial property right issues of bacteriophage-based biopesticides. When appropriately applied, bacteriophages can provide a promising tool against xanthomonads, a possibility that is untapped. Information presented in this review aims to explore the potential of bacteriophage-based biopesticides in the control of xanthomonads in the future

Attuazione di strategie IPM per controllare le malattie batteriche di drupacee e noci causate da pseudomonadi e xantomonadi resistenti/tolleranti al rame

Il cancro batterico delle drupacee causato da Pseudomonas syringae pv. syringae e Pseudomonas syringae pv. morsprunorum e il mal secco del noce causato da Xanthomonas arboricola pv. juglandis, sono stati studiati per oltre un secolo e hanno portato a significativi progressi nella nostra comprensione dell'epidemiologia delle malattie batteriche fogliari e del ciclo di vita epifita di questi agenti patogeni. Recenti studi sull'ecologia, la caratterizzazione e l'identificazione dei patogeni sono stati stimolati dall'importanza economica delle malattie e dalla mancanza di misure di controllo efficaci. Una collezione di 54 isolati di P. syringae spp. da albicocco e 47 isolati di X. a. pv. juglandis da noce sono stati studiati utilizzando il fingerprinting genomico mediante reazione a catena della polimerasi ripetitiva (PCR), utilizzando i set di primer ERIC, BOX e REP e l'analisi della sequenza multi-locus (MLSA). La tolleranza al rame di tutti i ceppi \ue8 stata valutata osservando la crescita batterica su terreni con aggiunta di solfato di rame e i risultati sono stati confrontati con quelli di uno studio di cinque anni nella stessa area. Questa tesi ha mostrato che la frequenza dei batteri resistenti al rame aumenta dopo ripetuti trattamenti con composti a base di rame. Questi risultati suggeriscono che la selezione di ceppi resistenti al rame pu\uf2 essere una delle principali cause di fallimento nel controllo dopo il trattamento con composti rameici. I batteriofagi, in quanto elementi naturalmente presenti nell\u2019ambiente, potrebbero essere un'opzione praticabile per il controllo di queste malattie batteriche. In questa tesi, dieci nuovi fagi che lisano P. s. pv. syringae e dieci nuovi fagi che lisano X. a. pv. juglandis sono stati isolati da frutti, foglie, suolo e acqua di irrigazione di albicocche e noci nel nord Italia. La digestione con endonucleasi di restrizione dei fagi ha rivelato che esistono tre gruppi fagici distinti, designati come gruppi 1, 2 e 3. Nonostante il fatto che tutti i fagi isolati fossero specifici per X. a. pv. juglandis, un'analisi della gamma ospite di fagi che coinvolge 25 diversi X. a. pv. juglandis ha rivelato che i fagi possono essere suddivisi in quattro classi in base alla loro capacit\ue0 di lisare i 25 ceppi considerati. Nei test di laboratorio, tutti i fagi hanno avuto un promettente effetto litico su P. s. pv. syringae e X. a. pv. juglandis.Bacterial canker of stone fruits caused by Pseudomonas syringae pv. syringae and Pseudomonas syringae pv. morsprunorum, and bacterial blight of walnut caused by Xanthomonas arboricola pv. juglandis, have been studied for over a century and have resulted in significant advances in our understanding of the epidemiology of foliar bacterial diseases and epiphytic life cycle of these pathogens. Recent studies on the ecology, characterization, and identification of pathogens have been prompted by the economic importance of the diseases and the lack of effective control measures. A collection of 54 P. syringae spp. on apricot and 47 X. a.pv. juglandis strains on walnut were studied using repetitive polymerase chain reaction (PCR) genomic fingerprinting using ERIC, BOX, and REP primer sets, and Multi-Locus Sequence Analysis (MLSA). Copper tolerance of all strains were assessed by observing bacterial growth on copper sulphate-added media, and the results were compared to those of a five-year-old study in the same area. This thesis showed that the frequency of copper resistant bacteria increased after repeated treatments with copper-based compounds. These findings suggest that the selection of copper-resistant strains may be a major cause of control failures after copper bactericide treatment. Bacteriophages, as realistic and environmentally friendly microorganisms, could be a viable option for controlling these bacterial diseases. In this thesis, ten novel phages that lyse P. s. pv. syringae and ten novel phages that lyse X. a. pv. juglandis were isolated from apricot and walnut fruits, leaves, soil, and irrigation water in Northern Italy. The restriction endonuclease digestion of phages revealed that there are three distinct phage groups, designated as groups 1, 2, and 3. Despite the fact that all isolated phages were specific to X. a. pv. juglandis, an analysis of the host range of phages involving 25 different X. a. pv. juglandis strains revealed that the phages can be divided into four classes based on their ability to lyse the 25 strains considered. In laboratory tests, all phages had a promising lytic effect on P. s. pv. syringae and X. a. pv. juglandis. P. s. pv. syringae and X. a. pv. juglandis showed promising lytic effect in laboratory trials

Le batteriosi delle drupacee, un problema di non facile soluzione

Da diversi anni, però, i frutticoltori italiani lamentano serie difficoltà nel mantenere la produttività degli impianti a causa di frequenti scoppi epidemici di alcune malattie batteriche che sono responsabili della comparsa di sintomi a carico dei frutti, foglie e parti legnose degli alberi

Respuesta de áfidos depredadores a compuestos volátiles sintéticos en un huerto de manzana

The indirect defence compounds termed herbivore induced plant volatiles (HIPVs), which are used to attract beneficial fauna, are one of the most effective biological control tools for the aggregation of natural enemies of key pests. The aim of this study was to test the attraction of three aphid predators of the Chrysopidae, Coccinellidae and Syrphidae families using synthetic formulations of four main HIPVs [methyl salicylate (MeSa), benzaldehyde (B), linalool (L) and farnesene (F)] alone and in binary combinations (MeSa + B; MeSa + F; MeSa + L; F + B; B + L; F + L) in an apple orchard in the Bursa province of Turkey. This study was the first demonstration of the attraction of these aphid predators to single and binary combinations of synthetic HIPVs in an apple orchard. A larger number of coccinellids were captured using single treatments of both B and F than with other HIPV combinations. Furthermore, the chrysopid individuals studied were significantly attracted to traps baited with single HIPVs. In addition, the binary combination of MeSa + L significantly attracted more Syrphids than in both single treatments and control traps. Thus, some of the HIPV’s tested were found to have potential value for the congregation of aphid predators in apple orchards.Los compuestos de defensa indirectos, denominados compuestos volátiles de plantas inducidos por herbívoros (HIPV por su sigla en inglés), al atraer fauna benéfica, son una de las herramientas de control biológico efectivas para la agregación de enemigos naturales de plagas claves. El objetivo de este estudio fue evaluar la atracción de formulaciones sintéticas de cuatro HIPV principales: [salicilato de metilo (MeSa), benzaldehído (B), linalool (L) y farneseno (F)], solos y en combinaciones binarias (MeSa + B; MeSa + F; MeSa + L; F + B; B + L; F + L) a tres depredadores de áfidos de las familias Chrysopidae, Coccinellidae y Syrphidae en una plantación de manzanas de la provincia Bursa, en Turquía. Este estudio representa la primera evidencia de la atracción que ejercen combinaciones únicas y binarias de HIPV sintéticas a depredadores de áfidos en un manzanar. Relativamente, un mayor número de coccinélidos fue capturado por los tratamientos individuales de B y F en comparación con otras combinaciones de HIPV. Los individuos de crisópidos fueron más atraídos significativamente a las trampas cebadas con estos HIPV sólos. Además, la combinación binaria de MeSa + L atrajo significativamente más sírfidos que sus tratamientos únicos y trampas de control. Por lo tanto, se encontró que algunos de los HIPV evaluados tenían un valor potencial en la atracción de depredadores de áfidos en los manzanos

BACTERIOPHAGE-BASED BIOCONTROL AGAINST PLANT PATHOGENIC BACTERIA

Bacterial plant diseases can cause significant economic losses worldwide. There is an urgent need for the development and application of sustainable biocontrol agents against plant pathogenic bacteria. Bacteriophages are promising antimicrobial agents, as it was demonstrated for five phytopathogenic bacteria. Phages infecting Acidovorax citrulli, causing seedling blight and bacterial fruit blotch of cucurbits, were isolated and characterized. Lytic life cycle and some of the biological characteristics of investigated phage strains indicated their potential in the control of watermelon fruit blotch. Xanthomonas euvesicatoria causes bacterial spot disease of pepper and tomato. Phage KΦ1 was isolated from the rhizosphere of pepper plants showing symptoms of bacterial spot. Foliar applications of the unformulated KΦ1 phage suspension effectively controlled pepper bacterial spot compared to the standard treatment and the untreated control. Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating agent of rice, causing its bacterial leaf blight (BLB). We isolated and characterized ten OP2-like bacteriophages. Laboratory efficacy trials strengthened the hypothesis that these bacteriophages can control BLB effectively. A bacteriophage cocktail protected rice plants against Xoo successfully during a field trial. Xanthomonas arboricola pv. juglandis (Xaj) causes walnut blight disease. Bacteriophages against Xaj were isolated from Italian and Hungarian samples and characterized. Two phages were tested individually for their ability to suppress symptoms in walnut plantlets following bacterial inoculation. A significant reduction in the degree of symptoms was observed following phage application when compared to the control. We formulated a cocktail containing six bacteriophages and implemented field trials by spraying the phage suspension on different Juglans regia varieties. The applied bacteriophage cocktail protected walnut trees against Xaj effectively, albeit the efficacy was different depending on which variety was treated. Erwinia amylovora causes fire blight disease of Rosaceae plants. 125 bacteriophages were isolated from soil, and aerial samples were taken in Hungary, Romania, and Spain, from which 55 showed lytic plaque morphology. Based on host range analysis conducted on 101 bacterium strains, 27 phages were subject of detailed characterization. The applied bacteriophage cocktail carefully formulated protected apple trees against E. amylovora during two field trials. A special permit was issued for marketing the Erwiphage bacteriophage-based biopesticide in 2012. This product was the first bacteriophage- based biocontrol agent against E. amylovora and the second one among all bacteriophages-based biopesticide that was available on the market worldwide. Our results support that bacteriophages are potent biocontrol agents against phytopathogenic bacteria.https://enauka.gov.rs/handle/123456789/92283