73 research outputs found
First report of «Cadophora malorum» on «Asparagus officinalis» in Italy
In this note Cadophora malorum infections on asparagus plants cultivated in different localities in the
Foggia area (southern Italy) are reported. Pathogenicity tests demostrated that C. malorum showed the capacity to
infect healthy plants of asparagus even if this capacity is less pronounced than that of Fusarium oxysporum f. sp.
asparagi and F. proliferatum
First report of pitch canker caused by Fusarium circinatum on Pinus halepensis and Pinus pinea in Apulia (Southern Italy)
Since 2005, pitch canker symptoms have been observed in Apulia (southern Italy, 41°27′42.84″N, 15°33′0.36″E) on numerous trees of Pinus halepensis and P. pinea in urban parks and gardens. Trees showed crown decline as a consequence of dieback of twigs and branches and withering of needles. Bleeding cankers with abundant resin were visible on twigs and branches. The needles of affected twigs and branches wilted, faded, turned yellow, then red, and were discarded. Isolations from symptomatic needles, twigs, and branches were performed on water agar, potato dextrose agar (PDA), and pentachloronitrobenzene medium. A species of Fusarium was consistently isolated from all infected tissues, and pure cultures were obtained by single hyphal tip transfers on PDA and synthetic nutrient agar medium (2). Colonies were incubated at 22 ± 3°C for 7 to 10 days. They produced white aerial mycelia, violet pigment, typically 3-septate macroconidia with slightly curved walls, single-celled microconidia, and characteristic sterile hyphal coils. Microconidia were ovoid or allantoid and born in false heads on aerial polyphialides. The species was identified as Fusarium circinatum Nirenberg & O'Donnell (= F. subglutinans Wollenweb & Reinking) on the basis of morphological and cultural characteristics (3). The identification was confirmed by PCR with specific primers CIRC1A/CIRC4A. The specific primer pair amplified a 360-bp DNA fragment of the two nuclear ribosomal IGS region (4). The pathogenicity of three Italian isolates of F. circinatum from Pinus spp. (Fc1640, Fc1642, and Fc1643 stored in the collection of Dipartimento Scienze Agroambientali, Chimica and Difesa Vegetale, University of Foggia) was evaluated by artificial inoculations on 2-year-old potted seedlings of P. halepensis, P. pinea, P. nigra, P. sylvestris, P. domestica, P. pinaster, P. excelsa, P. radiate, and Pseudotsuga menziesii (10 seedlings for each species and fungal isolate). Small PDA plugs from actively growing colonies of F. circinatum were introduced into a U-shaped cut on the stem of the seedlings and wrapped with moist sterile cottonwool. An equal number of control plants of each Pinus spp. was inoculated with sterile agar. All plants were grown in a nursery at ambient temperature (20 to 28°C). Within 30 days after inoculation, resinous cankers appeared on the stem of the seedlings of P. halepensis, P. pinea, P. domestica, P. pinaster, and P. radiata. Basal needles began to wilt, turn yellow, then red, and were discarded. F. circinatum was reisolated from stems of symptomatic seedlings. No symptoms were observed on seedlings of Pseudotsuga menziesii, P. sylvestris, P. excelsa, and P. nigra or on control seedlings. In Europe, pitch canker caused by F. circinatum previously has been reported only in Spain on P. radiata and P. pinaster (1). There was an unconfirmed report of this disease in Italy (http://www.eppo.org), but to our knowledge, this is the first definite conclusive evidence of the presence of pitch canker of pine in Italy
The fungus Nectria aurantiicola Berk. et Br. (Fusarium larvarum Fuckel) a biocontrol agent of the armored scale Suturaspis archangelskyae (Lindinger) in Apulia (Southern Italy)
Suturaspis archangelskyae [(Lindinger) 1929] (Homoptera, Diaspididae), an armored scale insect collected in Apulia (Italy) on Prunus dulcis (Miller) D. A. Webb (=almond) and Prunus webbii (Spach) Vierh., is reported to be infected by Fusarium larvarum Fuckel. The cycle of the fungus, as studied on female lineage of S. archangelskyae, shows mycelium in August and September, orange sporodochia from November to March, while mature red perithe- cia of the teleomorph Nectria aurantiicola Berk. et Br. are observed since middle January up to the first half of February. The fungus survives during the hot dry season as mycelium in the dead body of the host. The fungus is able to kill about 50% of the scales and spreads among demes by conidia carried on crawlers. Both varieties, the creamy var. larvarum Fuckel and the carmine-red var. rubrum Gerlach, are found on natural infected scales. The male progeny of S. archangelskyae seems not to be affected by the fungus. Ascospores are observed as well, but their role in pathogenesis remains unknown. Fusarium larvarum seems to be the main “natural” biocontrol agent (sensu Rosen et DeBach, 1990) of S. archangelskyae in Apulia. Key words: semi-arid (mediterranean) habitat, entomopathogens, pathogenic symbiosis, armo- red scale, coccids, Cheyletidae (Acari preying crawlers), biology, Puglia. NECTRIA AURANTIICOLA BERK. ET BR. (FUSARIUM LARVARUM FUCKEL) ANTAGONISTA DI SUTURASPIS ARCHANGEL- SKYAE (LINDINGER) IN PUGLIA (ITALIA MERIDIONALE) Gli autori descrivono la simbiosi fra un fungo entomopatogeno, Fusarium larvarum Fuckel (teleomorfo Nectria aurantiicola Berk. et Br.), ed il diaspino Suturaspis archangelskyae (Lindinger, 1929) su Prunus dulcis (Miller) D. A. Webb e P. webbii (Spach) Vierh. presso “Castel del Monte” (Andria, BA) ed in numerose località della Puglia. Sono state osservate le modalità di disseminazione del fungo ed il procedere dell’infezione, che culmina con l’uccisione delle cocciniglie prima che queste possano riprodursi. Durante i mesi invernali il fungo produce sporodochi reniformi di colore arancio, ricchi di conidi falciformi, e periteci globoso-piriformi di colore rosso arancio, contenenti le ascospore. Il fungo risulta essere il principale fattore biotico limitante del diaspino del quale uccide le femmine adulte. Esso sembra suscettibile di utilizzo come agente di controllo biologico per inoculazione od incremento, sempre che vengano assicurati a fondo i fattori, ecologici che regolano l’infezione. Aspetto favorevole all’uso di F. larvarum nelle regioni temperate è la sua predilezione per le temperature moderate. Non è stato possibile chiarire il ruolo delle ascospore nella diffusione del fungo. Parole chiave: mandorlo, habitat semi-aridi (mediterranei), coccoidei, Cheyletidae (Acari predatori di neanidi)
phytophthora cinnamomi involved in the decline of holm oak quercus ilex stands in southern italy
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Colletotrichum clavatum sp. nov. identified as the causal agent of olive anthracnose in Italy
Molecular analyses of a large population of isolates, previously identified as group B or genetic group A4 of the Colletotrichum acutatum species complex, mainly of Italian origin from olive, but also from other hosts collected since 1992, confirmed a well-resolved phylogenetic lineage with distinctive phenotypic characters which can be recognized as a separate species. Based on RAPD genomic fingerprinting, ITS and β-tubulin DNA sequences, this species was clearly distinct from C. acutatum sensu stricto, C. fioriniae and C. simmondsii as well as from the genetic groups A1, A6, A7 and A8, all previously referred to as C. acutatum sensu lato. Group A4 is widespread in Europe, being responsible for olive anthracnose epidemics in some Mediterranean countries, including Greece, Italy, Montenegro, Portugal and Spain; moreover, it causes anthracnose diseases on a wide range of other hosts including about 20 different genera of woody and herbaceous plants, ornamentals and fruit trees. This new anamorphic taxon is described as Colletotrichum clavatum sp. nov
Parassiti fungini delle piante nell'Italia meridionale. III. Phaeosphaeria nodorum (MĂĽll.) Hed. su Frumento duro.
Parassiti fungini dell'Italia meridionale. V. Pseudoseptoria stomaticola (Bäuml.) Sutton su Orzo (Hordeum vulgare L.).
THE FUNGUS NECTRIA AURANTIICOLA BERK. ET BR. (FUSARIUM LARVARUM FUCKEL) A BIOCONTROL AGENT OF THE ARMORED SCALE SUTARASPIS ARCHANGELSKYAE (LINDINGER) IN APULIA (SOUTHERN ITALY)
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