Effects of 1-MCP and dynamic controlled atmosphere on apple fruit rot caused by Fusarium avenaceum

Fusarium species are increasingly detected as the causal agents of decay of stored apple fruits. Fusarium avenaceum is particularly significant due to its predominant occurrence among Fusarium species in stored apple fruits and its ability to produce mycotoxins. Treatments with 1-methylcyclopropene (1-MCP) and different storage conditions affect the aggressiveness of F. avenaceum and development of fungal-caused decay in stored apple fruits. In this study, apple fruits (cv. 'Granny Smith') were treated with 1-MCP, and artificially inoculated with F. avenaceum. The isolate used for inoculation, originating from apple fruit, was identified based on morphological characteristics and by polymerase chain reaction (PCR) using a species-specific primer pair (FA-ITSF and FA-ITSR) for F. avenaceum. After inoculation, treated and untreated fruits were stored at room temperature and cold-stored under dynamic controlled atmosphere (DCA). Diameters of necrotic lesions were measured after 7, 14 and 21 days of incubation on fruits stored at room temperature, while necrosis diameters on DCA-stored fruits were measured immediately at the end of storage period (143 days), and after 7, 14 and 21 days of additional incubation at room temperature. The results show that treatment with 1-MCP inhibits the development of F. avenaceum on apple fruits during storage under DCA. However, after storage, i.e. during incubation at room temperature, no significant difference between 1-MCP-treated and untreated fruits was observed. On fruits stored at room temperature only, no difference between 1-MCP-treated and untreated fruits was observed. However, 1-MCP-treated fruits stored at room temperature only developed significantly smaller necrosis lesions compared to 1-MCP-treated and DCA stored fruits. It infers that both 1-MCP treatment and DCA storage inhibit fungal decay caused by F. avenaceum on apple fruits. However, the effects do not persist after storage

Patogenost Pectobacterium spp. na krtolama različitih sorti krompira

Vrste Pectobacterium carotovorum subsp. brasiliense (Pcb) i Pectobacterium carotovorum subsp. carotovorum (Pcc) su tokom 2018. i 2019. godine na terioriji AP Vojvodine registrovane kao dominanatni prouzrokovači crne truleži prizemnog dela stabla i vlažne truleži krtola krompira. U postupku detekcije i identifikacije ovih prouzrokovača na simptomatičnim biljakama krompira tokom 2018. i 2019. godine, sekvenciranjem 16S rRNK regiona je za čak 90% dobijenih izolata potvrđena pripadnost vrsti Pcb. Godišnji gubici prinosa i kvaliteta krompira, usled delovanja ovih vrsta poprimaju sve veće razmere, te se one svrstavaju među deset ekonomski najznačajnijih fitopatogenih bakterija. Pored šteta koje nastaju u toku vegetacije, za vreme čuvanja krtola krompira u skladištu pa do njegove upotrebe, patogeni nastavljaju svoju aktivnost, te celokupne partije uskladištenih krtola mogu veoma brzo propasti. Najznačajniji izvor infekcije predstavljaju zaražene semenske krtole, te patogeni ovim putem imaju mogućnost lakog dospevanja u nova područja

Essential oils and hydrolates in control of plant pathogens

Under conditions of intensive plant production and intensive international trade with plant material, coupled with climate changes, plant pathogens became one of the major limiting factors in food and feed production. Besides these extremely favorable conditions for reproduction and dissemination of plant pathogens, resistance development to available control tools and ecotoxicological properties of these tools show that plant pathogen control has never been more challenging. Development of alternative, eco-friendly control tools against phytopathogens, became a necessity of contemporary agriculture. Essential oils are mixtures of complex volatile compounds. They are synthesized through secondary metabolic pathways in many plant species. Essential oils are normally extracted by hydro-distillation or steam distillation of plant tissues. Hydrolates are co-products of the distillation formed in significantly higher quantities than the target substance. Hydrolate represents aromatic water containing approximately 0.1% essential oil compounds

Uticaj etarskih ulja na Colletotrichum spp. – prouzrokovače gorke truleži jabuke

Fitopatogene gljive značajno ugrožavaju kvalitet plodova jabuke tokom skladištenja. Vrste Colletotrichum acutatum i Colletotrichum gloeosporioides, prouzrokovači gorke truleži (antraknoze) plodova jabuke, u pojedinim godinama prouzrokuju značajne gubitke. Colletotrichum spp. zarazu plodova jabuke ostvaruju pre berbe plodova, ali je zaraza moguća i posle ovog perioda. Zaštita plodova jabuke od prouzrokovača truleži se u najvećoj meri oslanja na primenu sintetičkih fungicida, pre berbe plodova. Zbog nepovoljnih ekotoksikoloških svojstava i pojave rezistentnosti, primena hemijskih fungicida tokom vegetacionog perioda se sve više redukuje, dok je njihova upotreba posle berbe plodova zabranjena u Evropskoj uniji, ali i u Srbiji. Imajući u vidu navedeno, kao i činjenicu da su zahtevi potrošača za zdravstveno bezbednom hranom sve izraženiji, istraživanja o alternativnim načinima borbe protiv patogena uskladištenih plodova voća sve više dobijaju na značaju. Etarska ulja pojedinih biljaka ispoljavaju snažno antifungalno dejstvo, te mogu biti potencijalni agensi zaštite plodova jabuke od prouzrokovača truleži

Vrste rodova Pectobacterium i Dickeya - prouzrokovači crne truleži prizemnog dela stabla i vlažne truleži krtola krompira

World potato production is affected by plant pathogenic bacteria, which significantly limit crop yield and quality in recent years. Bacteria belonging to Pectobacterium and Dickeya genera, causal agents of blackleg and tuber soft rot of potato, are considered as one of the most important pathogens that affect plant production worldwide. Main source of infection are latently infected seed tubers, which transmitted over long trade distances significantly increase disease incidence. Main identification tools for Pectobacterium and Dickeya species until recently were morphological and biochemical characterization methods, followed by pathogenicity tests. Due to phylogenetic heterogeneity of the soft rot and blackleg causing bacteria, identification and differentiation to species and subspecies level became increasingly difficult. Therefore, development of efficient and reliable identification methods is of high importance. Molecular and serological methods offer accurate, reliable and cost-effective differentiation of high specificity and reproducibility. This work aimed to review Pectobacterium i Dickeya species occurring on potato, with special highlight on available molecular identification techniques.Proizvodnja krompira u svetu značajno je ugrožena delovanjem fitopatogenih bakterija, te godišnji gubici prinosa poprimaju sve veće razmere. Među deset ekonomski najznačajnijih fitopatogenih bakterija koje smanjuju prinos i kvalitet poljoprivrednih kultura ističu se vrste rodova Pectobacterium i Dickeya - prouzrokovači crne truleži prizemnog dela stabla "crna noga" i vlažne truleži krtola krompira. Najznačajniji izvor infekcije su zaražene semenske krtole, te bakterije ovim putem lako dospevaju u nova područja. Identifikacija bakterija rodova Pectobacterium i Dickeya se do nedavno zasnivala na proučavanju morfoloških odlika bakterijskih kolonija uz upotpunjavanje testovima patogenosti i biohemijskim analizama. Zbog heterogenosti populacije patogena precizna identifikacija prouzrokovača vlažne truleži je dodatno otežana. S obzirom na potrebe za brzom i pouzdanom identifikacijom, u primenu su uvedene serološke i molekularne metode. Molekularne tehnike identifikacije, zbog svoje visoke specifičnosti, brzine izvođenja, pouzdanosti i ponovljivosti danas zauzimaju vodeće mesto u identifikaciji patogena. U radu su prikazane vrste rodova Pectobacterium i Dickeya koje se javljaju na krompiru, sa posebnim osvrtom na molekularne tehnike identifikacije

Trichoderma harzianum as a potential biological agent in control of the charcoal root rot of sugar beet

Sugar beet is one of the most profitable crops in Serbia. The charcoal root rot is an emerging disease of sugar beet that significantly reduces yield and affects the economic viability of production. The objectives of this research were to determine the antagonist activity of selected Trichoderma harzianum isolates (T1 to T13) on two Macrophomina phaseolina isolates in vitro using a dual culture test and a volatile compounds test, as well as in vivo. The efficacy of these treatments was compared to two commercial biopesticides (Bacillomix® Original and Trifender Pro®) and one synthetic fungicide (Funomil 700 WG®). The strongest inhibition in the dual culture test was observed in the treatment with T. harzianum T2 against both tested M. phaseolina isolates. Also, the volatile compounds produced by isolates T2 and T12 exhibited the strongest inhibitory effect on M. phaseolina isolates (from 48.22 to 62.75%). Differences in efficacy were found not only between tested Trichoderma isolates, but also between M. phaseolina isolates used for inoculation which indicates different susceptibility of pathogen population to bioagent. The in vivo test confirmed the strong antagonistic effect of the T. harzianum T2 and T12 isolates. Bacillomix® Original, Trifender Pro® and Funomil® 700 WG did not express satisfactory effects in pathogen control

Uticaj etarskih ulja i hidrolata etarskih ulja na razvoj prouzrokovača gorke truleži jabuke

Vrste roda Colletotrichum, prouzrokovači gorke truleži jabuke, predstavljaju jedne od najznačajnijih prouzrokovača truleži plodova jabuke u skladištu. Zbog dominantne zastupljenosti u odnosu na druge vrste ovog roda posebno su značajne vrste C. acutatum i C. gloeosporioides. S obzirom da upotreba fungicida nakon berbe i tokom skladištenja nije dozvoljena zbog njihovih nepovoljnih ekotoksikoloških svojstava, a plodovi ostaju nezaštićeni tokom skladištenja, neophodno je definisanje alternativnih rešenja. Prethodna istraživanja su dokazala značajan antifungalni potencijal etarskih ulja i njihovih hidrolata (sporednih proizvoda koji se dobijaju pri proizvodnji etarskih ulja), te mogu predstavljati adekvatnu zamenu fungicidima. U ogledu je ispitan uticaj etarskih ulja čubra (Satureja hortensis), bosiljka (Ocimum basilicum), muskatne žalfije (Salvia sclarea) i divljeg origana (Origanum vulgare), kao i hidrolata etarskih ulja čubra, bosiljka i muskatne žalfije na izolate KA7 (C. acutatum) i MRMCD6 (C. gloeosporioides)

Genome Sequence Resource of Fusarium graminearum TaB10 and Fusarium avenaceum KA13, Causal Agents of Stored Apple Rot

The filamentous fungus Fusarium graminearum is a well-known cereal pathogen and F. avenaceum is a pathogen with a wide host range. Recently, both species were reported as causal agents of apple rot, raising concerns about postharvest yield losses and mycotoxin contamination. Here, we report genome assemblies of F. avenaceum KA13 and F. graminearum TaB10, both isolated from fruits with symptoms of apple rot. The final F. avenaceum KA13 genome sequence assembly of 41.7 Mb consists of 34 scaffolds, with an N50 value of 2.2 Mb and 15,886 predicted genes. The total size of the final F. graminearum TaB10 assembly is 36.76 Mb, consisting of 54 scaffolds with an N50 value of 1.7 Mb, and it consists of 14,132 predicted genes. These new genomes provide valuable resources to better understand plant-microbe interaction in stored apple rot disease. [Graphic: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license

Morphological, Molecular, and Pathogenic Characterization of <i>Neofabraea alba</i>, a Postharvest Pathogen of Apple in Serbia

Neofabraea spp. is one of the major causal agents of the postharvest decay of apple fruit. Bull’s eye rot can cause fruit rot, as well as tree canker. In Serbia, during February and March, 2017 and 2018, 56.3% of collected stored rotten apple fruits were found to be infected with Neofabraea spp. Using polymerase chain reaction, phylogenetic analysis, and morphological characterization, Neofabraeaalba was identified as the causal agent of Bull’s eye rot. Twenty-five selected isolates were analyzed by DNA sequencing of the internal transcribed spacer and 16 S mitochondrial ribosomal RNA. The phylogenetic analyses provided information on the distance between Neofabraea spp., while merged phylogenetic tree was required to give insight and clarify the relationships between isolates of Neofabraeaalba. N. alba demonstrated pathogenicity on apple fruit as well as on branches, with significantly different aggressiveness among the isolates. Isolates were able to produce larger cankers and acervuli on apple branches with abundant sporulation All identified isolates were separated into two morphotypes and described based on their macromorphological characteristics on culture media. It was noticed that different culture media, pH, and temperature could affect macromorphological characteristics and development. Representative isolates were able to grow at a temperature range of 0 to 25 °C, above which only one isolate was able to grow on culture media. All isolates showed growth at a pH range of 2–10, with significant differences detected between isolates at different pH values. The type of cultivation medium significantly affected the size and shape of conidia, while the presence of the microconidia was recorded within isolates. The aim of this study was to identify the causal agents of Bull’s eye rot on stored apples in Serbia in the period 2017–2018 and characterize the obtained isolates based on pathogenic, morphological, physiological, and molecular criteria

Etarska ulja u suzbijanju prouzrokovača vlažne truleži krtola krompira iz roda Pectobacterium

Vrste roda Pectobacterium su proteklih godina postale jedne od deset najproučavanijih fitopatogenih bakterija. Pažnju zavređuju zbog sve učestalije pojave novih vrsta, ekstremnoj adaptivnosti različitim domaćinima i uslovima životne sredine. Intenzivna trgovinska razmena dovodi do povećanja mogućnosti dospevanja novih vrsta na udaljena područja proizvodnje krompira, uzimajući u obzir da je glavni izvor inokuluma zaražen vegetativni materijal namenjen za sadnju. Štete uzrokovane vrstama Pectobacterium dosežu velike razmere, s obzirom na to da svoju aktivnost nastavljaju i po završetku vegetacije – prilikom transporta, prerade i u uslovima skladišta. Suzbijanje ovih patogena postaje ekstremno zahtevno uzimajući u obzir opšti nedostatak baktericida, te su mnogobrojni napori učinjeni sa ciljem iznalaženja načina suzbijanja prouzrokovača vlažne truleži krtola u uslovima skladišta. Mnoga istraživanja ukazuju na visoku efikasnost biljnih ekstrakata i etarskih ulja, kao moćnih agenasa zaštite. U cilju utvrđivanja efekata etarskih ulja (EU) bosiljka (Ocimum basilicum), čubra (Satureja hortensis), divljeg origana (Origanum vulgare), vreska (Calluna vulgaris) i timjana (Thymus vulgaris) na vrste P. carotovorum (Pc), P. brasiliense (Pb) i P. punjabense (Pp), sproveden je ogled in planta, na krtolama krompira sorte Lady Claire, jedne od najosetljivijih sorti na Pectobacterium spp