The effect of the culture filtrates, crude organic extracts of culture filtrates, metabolites such as scytalone, pullulan and oligosaccharides produced by three fungi associated with esca, ...Phaeomoniella chlamydospora (Pch), Phaeoacremonium aleophilum (Pal) and Fomitiporia punctata (Fop), on the growth of the fungi themselves, was studied in vitro. At 1:1 dilution, the culture filtrates of Pal and Pch inhibited Fop completely, whereas at 1:2 dilution they only increased Fop growth latency. Fop was not inhibited by crude organic extracts of Pal or Pch. Growth of Pal was slightly stimulated at the lowest concentration of Pch crude extracts, whereas it was inhibited at the highest concentration. Scytalone (at 1 mg ml*-1)), pullulan (at 0.2 mg ml*-1)) and oligosaccharides up to 2.5 kDa (2 mg ml*-1)) did not affect the radial growth of Fop
E' stato studiato in vitro l'effetto dei filtrati di coltura, estratti organici grezzi di filtrati di coltura, metaboliti come scitalone, pullulano e oligosaccaridi prodotti da tre funghi associati al mal dell'esca, Phaeomoniella chlamydospora (Pch), Phaeoacremonium aleophilum (Pal) e Fomitiporia punctata (Fop), sulla crescita degli stessi funghi. Alla diluizione 1:1, i filtrati di coltura di Pal e Pch inibivano completamente Fop, mentre alla diluizione di 1:2 essi facevano solamente aumentare il periodo di latenza della crescita di Fop. Fop non era inibita dagli estratti organici grezzi di Pal e Pch. La crescita di Pal era stimolata leggermente alla concentrazione piu' bassa degli estratti grezzi di Pch, mentre veniva inibita alla concentrazione piu' elevata. Lo scitalone (a 1 mg ml*-1)), il pullulano (a 0,2 mg ml*-1)) e gli oligosaccaridi fino a 2,5 kDa (2 mg ml*-1)) non influenzavano la crescita radiale di Fop
The disease of grapevine known as excoriose has been the source of a certain amount of controversy. Much of this concerns the identity of the casual agent and this has been further confounded by the ...taxonomic problems of the fungal pathogens associated with this disease. Many of these problems have now been resolved and it is clear that excoriose is caused by Botryosphaeria dothidea, while cane blight and leaf spot is caused by Phomopsis viticola. However, although at least five different species of Phomopsis are currently known to be associated with grapevines, only P. viticola causes cane blight and leaf spot. The role played by the other species of fungi is not clear, but they may be weak pathogens, saprophytes or endophytes
La malattia della vite conosciuta come escoriosi e' stata oggetto di numerose controversie. Molte di queste riguardano l'identita' dell'agente casuale e questo e' stato ulteriormente complicato dai problemi tassonomici relativi ai patogeni fungini associati a questa malattia. Molti di questi problemi sono stati ora risolti ed e' chiaro che l'escoriosi e' causata da Botryosphaeria dothidea, mentre l'avvizzimento dei tralci e la maculatura delle foglie sono causati da Phomopsis viticola. Comunque, sebbene oggi siano note cinque specie diverse di Phomopsis associate alla vite, solo P. viticola causa queste patologie. Il ruolo giocato dalle altre specie di funghi non e' chiaro, ma essi possono essere patogeni deboli, saprofiti o endofiti
Cross-inoculation experiments were carried out in southern Italy (Apulia) on grapevines cv. Italia and Matilde in order to study interactions among the white rot fungus Fomitiporia punctata (Fop) and ...two tracheiphilous hyphomycetes, Phaeoacremonium aleophilum (Pal) and Phaeomoniella chlamydospora (Pch), commonly associated with esca and brown wood-streaking of grapevine. In January 1999 the three fungi were inoculated through wounds on the trunks and spurs of cv. Italia, and branches and spurs of cv. Matilde. Pch, Pal and Fop were inoculated singly or in groups of two or three in all possible combinations. From the results so far obtained, the following conclusions can be drawn: 1. all three fungi are pathogenic; 2. inoculation of the above fungi on standing grapevines produces symptoms on trunks, shoots, leaves and berries that are reminiscent of those shown by esca-affected vines in the vineyard. In particular, symptoms in the wood (brown streaking, gummosis or "black goo", and wood decay or white rot), and on the leaves (various forms of chlorosis, reddening and necrosis, distortion of the lamina) and berries (black measles) were reproduced; 3. severity of internal symptoms, assessed as length of brown streaks and intensity of colour change of the infected wood, varied with the growth and interactions between the inoculated fungi; 4. the wood streaking which developed after inoculation with Pal or Pch on the spurs extended to the supporting shoot or branch, and even to the stem; 5. a non-synergistic, competitive association of the two hyphomycetes, and an inhibition of Fop growth by Pal was observed in planta. A similar marked antagonistic effect of Pal againsi Fop was previously shown to occur when examining interactions between the three fungi in vitro; 6. the wood discolouration caused by Fop was not hampered by Pch, but it is always limited by Pal; 7. on the basis of internal symptoms, grapevines cv. Italia were more susceptible to the esca fungi than grapevines cv. Matilde.
In the last decades, the population structure of some plant pathogenic bacteria has been assessed by using neutral markers. However, the dynamics of such populations as well as host plant and ...environment selection, gene flow and genetic drift, have been analysed to a lesser extent. Insights into the sequential adaptation occurring between the crop and the micro-organism can also contribute to achieve a more effective control of the disease in the long run. In this review, the possible centre of origin, often in relation to the geographic history of the crop, is discussed for some phytopathogenic bacteria, such as Xanthomonas axonopodis pv. citri, Xanthomonas axonopodis pv. cassavae, Xanthomonas oryzae pv. oryzae, Erwinia amylovora and Xylella fastidiosa. The rapid genetic change of bacteria through lateral gene flow and the efficient exploration of new adaptive solutions by exploiting the "contingency genes" of mutator clones might also explain the occurrence of new diseases. Host selection, changes in environmental conditions and the introduction of new agronomic techniques can play an important role in structuring the bacterial populations and in dramatically altering the equilibrium between the host plant and the pathogen. The prediction of such disturbances of equilibrium is fundamental for disease management
Nelle ultime decadi la struttura delle popolazioni di alcuni batteri fitopatogeni è stata valutata utilizzando marcatori neutri. Tuttavia, la dinamica di tali popolazioni, come pure la selezione da parte della pianta ospite e dell´ambiente, il flusso genico e la deriva genetica, sono stati analizzati in minor misura. La percezione dell´adattamento sequenziale che si verifica fra la coltura e il microrganismo può contribuire anche a ottenere un controllo più efficace della malattia nel lungo periodo. In questa rassegna viene discusso il possibile centro di origine, spesso in relazione alla storia geografica della coltura, di alcuni batteri fitopatogeni, come Xanthomonas axonopodis pv. citri, Xanthomonas axonopodis pv. cassavae, Xanthomonas oryzae pv. oryzae, Erwinia amylovora e Xylella fastidiosa. Pure il rapido cambiamento genetico dei batteri tramite il flusso genico laterale e l´esplorazione efficace di nuove soluzioni adattative mediante l´utilizzazione di "geni di contingenza" di cloni mutator potrebbero spiegare il verificarsi di nuove malattie. La selezione dell´ospite, i cambiamenti delle condizioni ambientali e l´introduzione di nuove tecniche agronomiche potrebbero giocare un ruolo importante nella strutturazione delle popolazioni batteriche e nell´alterazione drastica dell´equilibrio fra la pianta ospite e il patogeno. La previsione di tali alterazioni dell´equilibrio è fondamentale per la gestione delle malattie.
Twenty healthy cuttings each were inoculated artificially with Phaeomoniella chlamydospora Phaeoacremonium inflatipes and Phaeoacremonium aleophilum. After the formation of callus, they were planted ...in pots. Approximately one year after inoculation, disease occurrence was recorded as the length of brown vascular streaking from the base of plant toward the shoot tip. Discolored areas were cultured on potato dextrose agar amended with tetracycline hydrochloride (PDA-tet) and pathogens were re-isolated. Inoculation with Pa. chlamydospora showed that rootstocks 3309, 420A, 110R, 5C, Schwarzmann, St. George, and Salt Creek were least susceptible, while 99R, 39-16, Freedom, Riparia Gloire, 140Ru, 16-16 and 1103 were most susceptible. When inoculated with Pm. inflatipes, 16-16,3309, AXR1, Salt Creek, 110R, 5C, Freedom and 140Ru were least susceptible, while 420A, St. George, 161-49, and Harmony were most susceptible. Inoculation with Pm. aleophilum showed that 1103, 420A, Harmony, and Salt Creek were least susceptible, while 110R, SO4, 39-16 and 161-49 were most susceptible. The susceptibility of the rootstocks and the occurrence of vine decline in the field in California did not appear to be well correlated because 3309, 101-14, 5C, and 110R were always most susceptible. But these rootstocks are the most widely planted, and hence the natural occurrence of the disease is probably skewed towards these rootstocks. However, since no resistance was detected in our study, even though there was a wide range of susceptibility, the degree of rootstock susceptibility may not be such an important factor in disease expression under natural conditions.
Glavni cilj ovoga istraživanja bio je izolirati gljive iz zraka i procijeniti sezonske promjene u onečišćenju zraka gljivičnim propagulama u naosu i egzonarteksu istraživane crkve. Također su praćeni ...mikroklimatski parametri kao ograničavajući čimbenici za razvoj i rast gljiva na zidnim slikama, za oslobađanje spora i njihovu transmisiju kroz zrak. Zabilježena temperatura i relativna vlažnost zraka u naosu pogodovale su razvoju i rastu gljiva. Dokumentirana su 33 taksona gljiva, uglavnom pripadnika koljena Ascomycota, a manje su zastupljeni oni Zygomycota i Basidiomycota. Najčešće su bile prisutne plijesni rodova Penicillium (23,55 %) i Aspergillus (20,58 %). Sørensenov indeks sličnosti (0,37) upućuje na stalnu i umjerenu razmjenu gljivičnih propagula između naosa i egzonarteksa. Uzorci uzeti u jesen pokazali su najveću raznolikost sa 17 zabilježenih taksona, a oni uzeti u proljeće samo osam taksona. Kvantitativna mikološka analiza u naosu (430±84,85 do 1880±106,07 CFU m-3) i egzonarteksu (715±59,62 do 2295±91,92 CFU m-3) pokazala je visoku godišnju razinu onečišćenja zraka, s vrijednostima koje prema većini standarda prelaze dopuštene koncentracije. Mnoge identificirane gljive mogu dovesti do biodeterioracije, proizvesti mikotoksine i izazvati alergijske reakcije. Stoga su nepoželjne u sakralnim objektima ne samo zbog očuvanja murala nego i zbog zaštite zdravlja zaposlenih, posjetitelja i konzervatora.
Antifungal activities of extracts from selected Lebanese wild plants against plant pathogenic fungi Abou-Jawdah, Y. (American Univ. of Beirut (Lebanon). Dept. of Plant Sciences); Wardan, R. (American Univ. of Beirut (Lebanon). Dept. of Plant Sciences); Sobh; H. (American Univ. of Beirut (Lebanon). Dept. of Plant Sciences) ...
Phytopathologia mediterranea,
12/2004, Volume:
43, Issue:
3
Journal Article
Peer reviewed
Open access
Extracts of nine plant species growing wild in Lebanon were tested for their efficacy against seven plant pathogenic fungi: Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., ...Fusarium oxysporum f. sp. melonis, Rhizoctonia solani and Sphaerotheca cucurbitae. Extracts of three of the plants, Origanum syriacum, Micromeria nervosa and Plumbago maritima, showed the highest levels of in vitro activity against spore germination and mycelial growth of the tested fungi. Inula viscosa showed high activity against spore germination but only moderate activity against mycelial growth. The other five plant species tested, Calamintha origanifolia, Micromeria juliana, Ruta sp., Sideritis pullulans and Urginea maritima, showed only moderate to low activity against these fungi. Preventive sprays with extracts of O. syriacum, M. nervosa, P. maritima and I. viscosa, applied at concentrations ranging between 4 and 8% to squash and cucumber seedlings, gave efficient protection against grey mold caused by B. cinerea and powdery mildew caused by S. cucurbitae. However, these extracts did not control green mold of citrus fruits caused by Penicillium sp.. Thin layer chromatography revealed three inhibitory bands in extracts of O. syriacum, two in I. viscosa and only one in each of the other plants tested: M. nervosa, P. maritima, C. origanifolia and Ruta sp
E´ stata saggiata l´efficacia degli estratti di nove specie vegetali spontanee in Libano nei confronti di sette funghi fitopatogeni: Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, Rhizoctonia solani e Sphaerotheca cucurbitae. Gli estratti di tre specie, Origanum syriacum, Micromeria nervosa e Plumbago maritima, hanno dimostrato i livelli più elevati di attività in vitro nei confronti della germinazione delle spore e della crescita del micelio delle specie fungine considerate. Inula viscosa ha evidenziato un´attività elevata nei confronti della germinazione delle spore, ma solo un´attività moderata nell´inibizione della crescita del micelio fungino. Le altre cinque specie, Calamintha origanifolia, Micromeria juliana, Ruta sp., Sideritis pullulans e Urginea maritima, presentavano attività moderata o bassa nei confronti di questi funghi. Trattamenti preventivi con estratti di O. syriacum, M. nervosa, P. maritima e I. viscosa, a concentrazioni dal 4 all´8% a plantule di zucca e cetriolo, hanno fornito una protezione efficiente contro la muffa grigia causata da B. cinerea and l´oidio causato da S. cucurbitae. Tuttavia, questi estratti non controllavano la muffa verde degli agrumi causata da Penicillium sp.. La cromatografia su strato sottile ha permesso di rivelare the bande inibitorie negli estratti di O. syriacum, due in I. viscosa e solo una in ognuna delle altre piante studiate: M. nervosa, P. maritima, C. origanifolia e Ruta sp..
PDF