Phytopathologia Mediterranea <p><em>Phytopathologia Mediterranea</em> is an international open-access, peer-reviewed journal edited by the <a title="Mediterranean phytopathological union" href="" target="_blank" rel="noopener">Mediterranean Phytopathological Union</a>. The journal deals with the main areas of plant pathology as epidemiology, control, biochemical and physiological aspects, application of molecular biology techniques, applied to fungi, bacteria, phytoplasmas, viruses, viroids, nematodes, etc. Special attention is given to phytopathological problems of the Mediterranean area. The journal includes 3 issues per year in which a review paper, original research papers, short notes and new disease reports are published. It also includes Book reviews of interest for Mediterranean phytopathologists. Papers are published in English. Phytopathologia Mediterranea is covered by CAB, BIOSIS, AGRIS, Chemical Abstracts, CSA, JSTORE.</p> <p><em>Phytopathologia Mediterranea</em> is printed with the financial support of the Ministero per i Beni Culturali, Roma, Italy.</p> en-US <p>Authors retain the copyright and grant the journal right of first publication with the work simultaneously licensed under a <strong>Creative Commons Attribution 4.0 International Public License (<a href="">CC-BY-4.0</a>)</strong>&nbsp;that allows others to share the work with an acknowledgment of the work's authorship and initial publication in PHYTO</p> <p><a href="" rel="license"><img style="border-width: 0;" src="" alt="Creative Commons License"></a><br>This work is licensed under a <a href="" rel="license">Creative Commons Attribution 4.0 International License</a></p> (Editorial Office) (Alessandro Pierno) Sat, 15 Dec 2001 00:00:00 +0000 OJS 60 Young Esca in Australia Young esca was monitored on 3 to 7-year-old grapevines in two vineyards in the Riverland region of Australia over two seasons (1999–’00 and 2000–’01). The affected cultivars were own-rooted Shiraz, own-rooted Cabernet Sauvignon and Merlot grafted onto Kober 5BB. Some of the Cabernet Sauvignon vines began to show symptoms as young as two-years-old. Phaeomoniella chlamydospora was the only esca-associated fungus consistently isolated from symptomatic vines, suggesting that P. chlamydospora alone is responsible for esca symptoms. Spatial analysis was unable to reveal any consistent pattern of symptom distribution. Guido Marchi, Ian G. Pascoe, Jaqueline Edwards Copyright (c) 2001 Guido Marchi, Ian G. Pascoe, Jaqueline Edwards Thu, 30 Jun 2022 10:47:11 +0000 Investigation into the Occurrence of Esca-Associated Fungi in Cuttings and Bench-Grafted Vines Rootstocks, scions, certified virus-free grafted plants and 1-year old plants were studied to determine the incidence of wood discoloration and the occurrence of fungi associated with esca. On cuttings very little discoloration was observed and fungal infection was negligible. The majority of grafts and vines showed blackening and harboured a variety of fungi, mainly Phaeoacremonium spp., with Phaeomoniella chlamydospora in second place. The presence of these fungi as endophytes requires further investigation to determine the conditions under which they become pathogenic and to determine when contamination of vine material occurs during nursery operations. Alessandro Zanzotto, Michele Borgo, Salvatorica Serra, Wanja Viel Copyright (c) 2001 Alessandro Zanzotto, Michele Borgo, Salvatorica Serra, Wanja Viel Thu, 30 Jun 2022 10:48:43 +0000 «Phaeoacremonium» Species and «Phaeomoniella chlamydospora» in Vines Showing «hoja de malvón» and Young Vine Decline Symptoms in Argentina Vines showing “hoja de malvón” and young vine decline symptoms in Argentina have been examined for the presence in the wood of Phaeomoniella chlamydospora, different species of Phaeoacremonium, and other fungi. In all the isolations from mature vines with hoja de malvón symptoms Phellinus sp. prevailed over Phaeoacremonium aleophilum, Pm. parasiticum, and Phaeomoniella chlamydospora. By contrast in young vines with decline symptoms the most prevalent fungi were species of Botryodiplodia. Pm. aleophilum was more frequently isolated than Pm. parasiticum either in mature or in young vines. This is the first time Pm. parasiticum was isolated from diseased grapevines. In mature vines Simple Correspondence Statistical Analysis showed that Pm. aleophilum was significantly associated with soft white rot and sectorial brown necrosis, and in terms of the portion affected, with the arms of the vine. Pa. chlamydospora was associated with necrosis of the brownish zone bordering the black line, with black spots, and with the base of the vine. Pm. parasiticum considered separately or together with Pm. aleophilum, was associated with black line necrosis, with the mid-trunk and with the primary vine branches. In young vines, Pa. chlamydospora was also associated with the base of the vine, Pm. aleophilum with the rootstock stem, and Pm. aleophilum and Pm. parasiticum with the grafting zone. Cecilia Césari, Joëlle Dupont, Martica Gatica, Sandrine Magnin Copyright (c) 2001 Cecilia Césari, Joëlle Dupont, Martica Gatica, Sandrine Magnin Thu, 30 Jun 2022 10:50:42 +0000 Fungi Associated with Esca and Grapevine Declines in Spain : A Three-Year Survey A survey of 140 vineyards in different production areas of Spain was conducted from 1999 to 2001 to identify pathogenic grapevine wood fungi. Fungal infected vines showed esca and decline symptoms, consisting mainly of reduced growth of canes and shoots, yellowing and necrotic spotting of leaves, sectorial and central brown necrosis of the trunk, soft rotted tissues and discoloured xylem at the base of the vines. Several fungi were consistently found associated with these symptoms: Botryosphaeria obtusa (isolated from 61.4% of all vineyards studied), Phaeoacremonium aleophilum (26.4%), Cylindrocarpon spp. (20%), Phaeomoniella chlamydospora (18.6%) and Fomitiporia punctata (15%) were the main fungi found. Less frequently isolated species were: Botryosphaeria dothidea (6.4%), Eutypa lata (2.1%), and Stereum hirsutum (1.4%). The association of these fungi and their role in esca disease and grapevine declines, as well as in the decline of young grapevines in Spain are discussed. Antonio Vicent, Francesc García-Figueres, José García-Jiménez, Josep Armengol, Laura Torné Copyright (c) 2001 Antonio Vicent, Francesc García-Figueres, José García-Jiménez, Josep Armengol, Laura Torné Thu, 30 Jun 2022 11:05:01 +0000 Fungi Associated with Esca and Young Grapevine Decline in Greece In the period 1998–2001 significant numbers of vine samples of different varieties, grafted onto different rootstocks, ready for out-planting or planted and declined a few months or years later, were collected or sent to our laboratory to investigate the presence of phytopathogenic fungi. Three hundred eighty rooted cuttings ready for outplanting, 1250 young vines planted and exhibiting decline symptoms in the first year of establishment, 82 vines two to nine years old and 27 old vines exhibiting the classical esca symptoms were examined. Isolations yielded the fungi Phaeomoniella chlamydospora, Fomitiporia punctata and Stereum hirsutum, as well as other fungi of the genera Phaeoacremonium, Cylindrocarpon and Botryosphaeria. The low incidence of these fungi isolated in a low percentage of samples suggested that they could not by themselves be the cause of young grapevine decline. Abiotic causes, such as lesions from improperly healed rootstock disbudding sites and graft unions made in the nursery, as well as improper storage and transportation conditions of the propagated material must also have played a role and made the decline more acute. The occurrence of the isolated fungi as endophytes and their role in the outbreak of grapevine decline remain to be investigated. Artenis Rumbou, Ioannis Rumbos Copyright (c) 2001 Artenis Rumbou, Ioannis Rumbos Thu, 30 Jun 2022 11:05:49 +0000 Observation on Black Dead Arm in French Vineyards Black dead arm was first identified in French vineyards in 1999. It produces symptoms in the vine wood, causing decline and eventually death. Previously, this disease was confused with esca because of the similarity of the foliar symptoms. Two forms of black dead arm, a mild and a severe form, were observed in French vineyards on Cabernet Sauvignon and Sauvignon. Isolations from 23 vines collected from four vineyards located in three viticultural districts of Bordeaux showed that the main fungi associated with the brown streaks were Botryosphaeria obtusa, B. dothidea and Trichoderma spp. Pathogenicity tests showed that B. obtusa and B. dothidea caused dark lesions on 1- year-old canes. Therefore, these two fungi merit further study to determine their role in causing black dead arm. Bernadette Dubos, Laurent Cere, Philippe Larignon, Ríng Fulchic Copyright (c) 2001 Bernadette Dubos, Laurent Cere, Philippe Larignon, Ríng Fulchic Thu, 30 Jun 2022 11:06:27 +0000 Characterisation of «Cylindrocarpon destructans» Isolates from Grapevines in Portugal The isolates of Cylindrocarpon destructans used in the present study were selected from a collection of isolates from rootstock nurseries and grapevines showing symptoms of decline in Portugal during the last few years. These isolates were compared on the basis of gross cultural morphology, micromorphology and pathogenicity. The most variable parameter was colony colour. Analysis of micro- and macroconidial size of cultures on “Spezieller Nährstoffarmer Agar” plus 0.1% yeast extract medium (SNAY) revealed that all isolates except one, could be clustered in a single group. On carnation leaf agar (CLA) medium, however, all isolates clustered in a single group. All C. destructans isolates were pathogenic on rooted grapevine cuttings of cv. Periquita under greenhouse conditions. Internal black-foot symptoms were seen in inoculated plants and the pathogen was reisolated from 60 to 100% of these plants. All C. destructans isolates caused a significant (P=0.05) decrease in the height of inoculated plants, and the majority also caused a significant (P=0.05) reduction in the number of roots. Cecìlia Rego, Helena Oliveira, Teresa Nascimento Copyright (c) 2001 Cecìlia Rego, Helena Oliveira, Teresa Nascimento Thu, 30 Jun 2022 11:16:24 +0000 Recovery of «Phaemoniella chlamydospora» and «Phaeoacremonium inflatipes» from Soil and Grapevine Tissues Rose Bengal Chloramphenicol Agar (RBCA) appears to be a suitable media for isolating Phaeoacremonium spp. and Phaeomoniella chlamydospora from soil, spore traps and plant tissue. Using the soil-plate method, populations of these organisms were recovered from the soil and surfaces of plant tissue from many different regions of California. In addition, in a few vineyard sites these fungi were recovered from dried plant sap, which had oozed from grapevine girdling wounds and from standing water under grapevine drip systems. RBCA, along with a filtering system, is a useful tool in determining the presence of Petri disease pathogens in vineyard soils, water, and plant tissues. This research presents the first report of the recovery of Phaeoacremonium inflatipes from soil and standing water under grapevines. Akif Eskalen, Susanne Rooney, W. Douglas Gubler Copyright (c) 2001 Akif Eskalen, Susanne Rooney, W. Douglas Gubler Thu, 30 Jun 2022 11:16:59 +0000 Detection of Cylindrocarpon Black-Foot Pathogens in Grapevine by Nested PCR Black-foot disease of grapevine has been associated with two closely related species of the genus Cylindrocarpon, C. destructans and C. obtusisporum. However, only C. destructans isolates could be obtained from young vines and diseased grapevine rootstock nurseries in Portugal. In the present study, an alternative to traditional methods of detection of Cylindrocarpon spp. fungi from infected grapevine is described. In 1996, Hamelin et al. designed species-specific primers (Dest1 and Dest4) for detection of C. destructans ITS variants from conifer seedlings. With these primers, a DNA fragment of 400 bp was produced by direct PCR using DNA extracted from cultures of C. destructans (60 isolates) obtained from grapevine plants. Whereas no fragments were detected when cultures of common wood grapevine fungi were analysed, an amplicon of the same size was obtained for isolates of C. obtusisporum revealing the failure of these primers to distinguish Cylindrocarpon species. The 400 bp fragment mentioned could also be produced by direct PCR after adding C. destructans to healthy grapevine tissue (cv. Periquita), followed by DNA extraction using frozen plant tissue in liquid nitrogen and polyvinylpyrrolidone (PVP) treatment. However, amplification failed to detect C. destructans in artificially inoculated grapevine plants (cv. Periquita). Consequently, a nested PCR was carried out by modifying the procedure described by Hamelin et al. The universal primer ITS4 and the fungus-specific primer ITS1F were used in a first-stage fungus-specific amplification, followed by a second-stage amplification with the primers Dest1 and Dest4 using the PCR products from stage one. This approach was found to be a simple and reliable method for collective detection of Cylindrocarpon spp. directly from infected grapevine tissues. Cecìlia Rego, Helena Oliveira, Teresa Nascimento Copyright (c) 2001 Cecìlia Rego, Helena Oliveira, Teresa Nascimento Thu, 30 Jun 2022 11:17:33 +0000 Specific SCAR Primers for Fungi Associated with Wood Decay of Grapevine RAPD (Random Amplified Polymorphic DNA) analysis, a technique based on the polymerase chain reaction, was applied to explore variation in 178 isolates of Fomitiporia punctata, 94 of Phaeomoniella chlamydospora and 34 of Phomopsis viticola, selected as being representative of fungal populations from different vineyards and locations. The analysis showed a broad genetic variability in F. punctata and a very high genetic uniformity in P. chlamydospora. With P. viticola, isolates belonging to different vegetative compatibility groups were investigated; the analysis evidenced high genetic similarity among isolates within groups and broad inter-group variation. For each pathogen, specific RAPD markers were selected, cloned and sequenced. The obtained sequences were used to design sequence-characterised amplified region (SCAR) primers specific for each pathogen. These are being used to develop molecular diagnostic tools. Angela Abbatecola, Crescenza Dongiovanni, Francesco Faretra, Maria Antonietta De Guido, Rita Milvia De Miccolis Angelini, Stefania Pollastro Copyright (c) 2001 Angela Abbatecola, Crescenza Dongiovanni, Francesco Faretra, Maria Antonietta De Guido, Rita Milvia De Miccolis Angelini, Stefania Pollastro Thu, 30 Jun 2022 11:20:25 +0000 The Contribution of Imperfections in Nursery Stock to the Decline of Young Vines in California ‘Petri disease’, as defined at the 2nd International Workshop on Grapevine Trunk Diseases (Esca and Grapevine Declines, September 14–15 2001, Lisbon, Portugal), is a condition associated worldwide with the decline of young vines contaminated by Phaeoacremonium and/or Phaeomoniella pathogens. Vines exhibit stunted development with vascular tissues characteristically exuding darkened gums when sectioned transversally. ‘Young Vine Decline’ (YVD), historically including the condition now known as Petri disease, is a term still used widely in California to describe unexpectedly poor performance of young vines exhibiting symptoms that include those associated with Petri disease. Examination of more than eight hundred thousand dormant nursery vines as well as new and established declining vineyards demonstrated that nursery stock defects and mechanical and biotic vineyard stresses were frequently associated with YVD in California. Rootstock shaft lesions and weak roots were most commonly associated with YVD in very young vineyards, while root system contamination by nematodes and fungal pathogens was frequently associated with YVD in older vineyards. James A. Stamp Copyright (c) 2001 James A. Stamp Thu, 30 Jun 2022 11:21:04 +0000 Three-Year Observation of Grapevines Cross-Inoculated with Esca-Associated Fungi 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 against 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. Antonio Graniti, Giovanni Bruno, Lorenzo Sparapano Copyright (c) 2001 Antonio Graniti, Giovanni Bruno, Lorenzo Sparapano Thu, 30 Jun 2022 11:21:39 +0000 Histological Investigations on Infection of Grape Roots and Shoots by «Phaeoacremonium» spp. Tissue-cultured grapevines cv. Cabernet Sauvignon were used to determine whether injury is a prerequisite to penetration of shoot and root tissue by Phaeoacremonium spp. and to ascertain the path of invasion inside the host. Uninjured and injured roots and shoots were inoculated with P. inflatipes and P. aleophilum at approximately 106 spores ml-1. Isolation and scanning electron microscopy observations showed that Phaeoacremonium spp. was capable of penetrating uninjured roots and shoots. Light microscopy observations of paraffin embedded sections showed that rapid spread of the fungus in roots was through the vascular tissues and intercellular spaces of the cortex. In the shoots, spread of the fungus was initially through the intercellular spaces of the epidermis, cortex, and pith; rapid spread apparently occurred in the intercellular spaces of the pith. Spores were seen in the pith area as well as in the xylem. Remote from the point of inoculation, hyphae were seen in the epidermis, cortex, pith, and vascular tissues without noticeable change in appearance of the invaded cells. Symptoms of the disease were observed in some plants 2 months after inoculation but isolations made in symptomless plants after 2 weeks showed the presence of the fungus in all parts of the plant. Ascunia J. Feliciano, W. Douglas Gubler Copyright (c) 2001 Ascunia J. Feliciano, W. Douglas Gubler Thu, 30 Jun 2022 11:22:07 +0000 Tylose Formation and Changes in Phenolic Compounds of Grape Roots Infected with «Phaeomoniella chlamydospora» and «Phaeoacremonium» Species The role of phenolic compounds in strengthening resistance of grapevine to young grapevine decline was analysed. The formation of tyloses has also been associated with this disease. A microscopic study showed that tyloses originated in parenchyma cells associated with the xylem and from there invaded the xylem lumen. As tyloses formed, there were changes in the cell wall, associated with the accumulation of crystalline structures. The cells surrounding the blocked xylem contained more polyphenolic compounds than the cells of intact xylem. Changes in the level and composition of polyphenolic compounds occurred in relation to the severity of infection. Tannin concentrations also increased with increasing numbers of xylem vessels containing tyloses. Root extracts added to fungal culture media inhibited mycelial growth of Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and Pm. inflatipes. Inhibition was greater with extracts from roots with tyloses, and was also correlated with polyphenol content. Extracts of the leaves, stems and berries of vines treated with Brotomax, which increases the biosynthesis of phenolic compounds, inhibited mycelial growth of the fungi compared to untreated control plants. Ana Gonzalez, Ana Ortuño, José Del Rio, Juana M. Botia, María D. Fuster, Pedro Gomez, Victor Frias Copyright (c) 2001 Ana Gonzalez, Ana Ortuño, José Del Rio, Juana M. Botia, María D. Fuster, Pedro Gomez, Victor Frias Thu, 30 Jun 2022 11:22:37 +0000 «Phaeomoniella chlamydospora»-Grapevine Interaction : Histochemical Reactions to Fungal Infection Histochemical reactions of one-year-old potted micropropagated vines (rootstock 1103 Paulsen) to inoculation with Phaeomoniella chlamydospora were studied. Microscopic examination of the vine wood showed that the fungus spread through the wood tissue, albeit slowly. Starting from the roots it required nine months to colonise the first 20-25 cm of the grapevine stems. The slow spread of P. chlamydospora is thought to be due to the defence response initiated by the vines: production of tyloses, including accumulation of phenols in the vessels and adjacent tissue, and the deposition of unidentified defence-response substances, probably stilbene-like substances from the cell-wall surrounding the infection Bruno Mori, Giuseppe Surico, Laura Mugnai, Lorena Troccoli, Roberto Calamassi Copyright (c) 2001 Bruno Mori, Giuseppe Surico, Laura Mugnai, Lorena Troccoli, Roberto Calamassi Thu, 30 Jun 2022 11:23:23 +0000 Pectic Enzymes Production by «Phaeomoniella chlamydospora» Polygalacturonase and polymethylgalacturonase activity was detected in 13 strains of Phaeomoniella chlamydospora as well as in filtrates of isolates of some related fungi (Phaeoacremonium aleophilum, P. inflatipes, P. rubrigenum). Tests consisted of growth and colorimetric assays on media designed to evaluate different pectic enzymes. Phaeomoniella isolates on the same medium did not differ greatly in their morphological and cultural characters, but pectinolytic activity differed among isolates. Giuseppe Surico, Guido Marchi, Laura Mugnai, Renato D'Ovidio, Serena Roberti Copyright (c) 2001 Giuseppe Surico, Guido Marchi, Laura Mugnai, Renato D'Ovidio, Serena Roberti Thu, 30 Jun 2022 11:23:53 +0000 Interactions between Three Fungi Associated with Esca of Grapevine, and Their Secondary Metabolites 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 concentrations 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. Alessandra Campanella, Giovanni Bruno, Lorenzo Sparapano Copyright (c) 2001 Alessandra Campanella, Giovanni Bruno, Lorenzo Sparapano Thu, 30 Jun 2022 11:24:36 +0000 Interaction between Esca-Associated Fungi, Grapevine Calli and Micropropagated Shoot Cultures of Grapevine Callus of the grapevine cv. Italia, micropropagated shoot cultures of the cv. Italia, Matilde and Sangiovese and callus of the tobacco cv. White Burley were cultivated on modified LS and MS-media. Phaeomoniella chlamydospora (Pch), Phaeoacremonium aleophilum (Pal) and Fomitiporia punctata (Fop) grew well in the presence of calli and vitroplants of all the grapevine cultivars which stimulated the growth of the fungi, but growth of the calli and vitroplants was reduced. All three fungi inhibited callus growth more strongly in grapevine than in tobacco. Fop had the greatest inhibitory effect on grapevine callus. Symptom severity also differed between cultivars. All three fungi invaded callus tissue after entirely overgrowing its surface. Hyphae were observed within the callus mass, where several cellular aggregates showed melanin-like deposits, particularly when invaded by Pal. On the foliar lamina of vitroplants symptoms were produced before and after the invasion of the plantlets by each fungus. Symptoms consisted in light green or chlorotic, rounded or irregular spots between the veins or along the leaf margin. The combination Pal vs. vitroplant gave the fastest host-pathogen response. The susceptibility or resistance of calli or vitroplants to escaassociated fungi could be a means to select grapevine for resistance to these fungi. Alessandra Campanella, Giovanni Bruno, Lorenzo Sparapano, Silvana De Leonardis Copyright (c) 2001 Alessandra Campanella, Giovanni Bruno, Lorenzo Sparapano, Silvana De Leonardis Thu, 30 Jun 2022 11:25:20 +0000 Association of Spores of «Phaeomoniella chlamydospora», «Phaeoacremonium inflatipes», and «Pm. aleophilum» with Grapevine Cordons in California Esca (black measles) of grapevine has long been known to occur wherever grapes are grown. Phaeomoniella chlamydospora and two species of Phaeoacremonium, Pm. inflatipes and Pm. aleophilum, have been associated with esca and Petri grapevine decline in major production regions of California. Though present in symptomatic grapevines and capable of causing foliar symptoms of esca, Phaeomoniella chlamydospora does not cause the typical symptoms on fruit. However, trapping studies showed that spores of Pa. chlamydospora, Pm. inflatipes and Pm. aleophilum were captured throughout the year in vineyards ranging from the north California coast to the southern San Joaquin Valley. They can be considered airborne fungi capable of being water-splashed by pruning or other wounds during part of their biological cycle. Trapping of spores coincided with rainfall events for Pa. chlamydospora and Pm. inflatipes, and to a lesser degree for Pm. aleophilum. However, this last species was trapped during periods of time when rainfall did not occur and was trapped longer into the summer. Akif Eskalen, W. Douglas Gubler Copyright (c) 2001 Akif Eskalen, W. Douglas Gubler Thu, 30 Jun 2022 11:25:58 +0000 Rootstock Susceptibility to «Phaeomoniella chlamydospora» and «Phaeoacremonium» spp. 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. Adalat Khan, Akif Eskalen, W. Douglas Gubler Copyright (c) 2001 Adalat Khan, Akif Eskalen, W. Douglas Gubler Thu, 30 Jun 2022 11:26:33 +0000 Spatial Distribution of Symptomatic Grapevines with Esca Disease in the Madrid Region (Spain) From 1998 to 2001 three vineyards in the three areas Arganda, San Martin de Valdeiglesias and Navalcarnero, included in the vine-growing region “Wines of Madrid”, were surveyed for esca incidence and spatial distribution of infected vines. Individual vines were recorded as “diseased” when they showed esca symptoms, both in summer surveys (symptoms on leaves, weak growth, short branches growth) and in winter surveys (necrosis of trunk and main branches). Data recorded over several years in the same vineyard and data from different vineyards in the same year were compared in order to study disease spread and possible primary sources of infection. Our results showed that: i) esca foliar symptoms were discontinuous from year to year; ii) the distribution of infected vines in the vineyard was random and, iii) the disease was not spread between adjacent vines. Aránzazu Avila, Cristina Redondo, Eloy Mateo-Sagasta, M. Luisa Tello Copyright (c) 2001 Aránzazu Avila, Cristina Redondo, Eloy Mateo-Sagasta, M. Luisa Tello Thu, 30 Jun 2022 11:27:21 +0000 Preliminary Evaluation of Variations in Composition Induced by Esca on cv. Trebbiano d'Abruzzo Grapes and Wines The present study examined the effect on quality caused by esca in both grape clusters and wines. In the last year (2000) of an eight-year survey of esca foliar symptoms, the vines of two cv. Trebbiano d’Abruzzo vineyards fell at the moment of grape clusters sampling, into 3 groups: 1. vines with esca symptoms; 2. vines that happened to be asymptomatic but that were known to be diseased because they had show leaf symptoms in at least one other survey year and 3. healthy vines. In a third vineyard, in the same growing area, grape clusters were sampled from vines with trunk renewal that had been restored and from unrenewed vines that had never shown esca leaf symptoms and were consequently presumed to be healthy. Preliminary results on grape clusters in the first two vineyards showed differences in composition between symptomatic vines on the one hand, and asymptomatic/diseased vines and healthy vines on the other, with symptomatic vines having lower levels of reducing sugars and a higher nitrogen concentration. As a result the alcohol content of wines from symptomatic vines was about 1% v:v lower than that of wines from the other two groups of vines. Grape clusters and wines from diseased/asymptomatic vines and healthy vines did not differ in the compositional parameters used in the test except for total polyphenols which gave contrasting data among the first two vineyards. In grape clusters and wines from the third vineyard the preliminary results likewise revealed no difference between vines with trunk renewal and unrenewed healthy vines. This finding would seem to corroborate the practice of trunk renewal as a means of restoring both vines and the quality of grape clusters. Research is continuing to evaluate the reliability of these results. Angelo Cichelli, Francesco Calzarano, Maurizio Odoardi Copyright (c) 2001 Angelo Cichelli, Francesco Calzarano, Maurizio Odoardi Thu, 30 Jun 2022 11:28:01 +0000 How Iron Could Be Involved in Esca Fungi Development Iron reduction capability was detected by ferrozine assay in Phaeomoniella chlamydospora, Phaeacremonium aleophilum and Fomitiporia punctata. On the other hand, the Chrome Azurol S (CAS) assay demonstrated that low molecular weight chelator agents were produced by P. chlamydospora, P. aleophilum, Libertella blepharis and F. punctata. Foliar analysis carried out at harvest showed higher levels of the iron in symptomatic than in asymptomatic leaves. Conversely, levels of the other transition metals (copper, manganese and zinc), and of calcium and magnesium were basically similar in symptomatic and asymptomatic leaves. A possible relationship between iron, esca fungi and host-plant was hypothesized. Di Marco, Stefano, Alessandro Mazzullo, Augusto Cesari, Fabio Osti Copyright (c) 2001 Di Marco, Stefano, Alessandro Mazzullo, Augusto Cesari, Fabio Osti Thu, 30 Jun 2022 11:28:35 +0000 Effects of Fungicides, «in vitro», on Germination and Growth of «Phaeomoniella chlamidospora» In vitro studies were conducted into the activity of 22 fungicides against Phaeomoniella chlamydospora, the cause of Petri disease(1). Mycelial growth of the pathogen was inhibited by the DMI fungicides, cyproconazole, bitertanol, tebuconazole, fenarimol, myclobutanil and prochloraz, which gave EC50 values of less than 0.2 mg l-1; by the benzimidazole fungicides, benomyl, carbendazim and thiophanate methyl, which gave EC50 values of less than 0.4 mg l-1; by the anilopyrimidines, pyrimethanil and cyprodinil/fludioxonil, which gave EC50 values of less than 0.02 mg l-1. The same fungicides had different effects on germination of conidia. All the DMI fungicides tested were relatively ineffective with EC50 values greater than 15 mg l-1 for germination. Of the benzimidazoles, only benomyl was relatively effective at reducing germination, with an EC50 value of 0.09 mg l-1, whereas the anilopyrimidines, alone or combined with phenylpyrrole, were effective with EC50 values of less than 0.1 mg l-1. Kresoxim-methyl, which is locally systemic, was effective at inhibiting mycelial growth and germination with EC50 values of 0.086 and 0.11 mg l-1 respectively. Of the contact fungicides tested, most were effective at reducing germination of P. chlamydospora conidia, since their EC50 values were much lower than the recommended field rates, but these fungicides were also much less effective at reducing mycelial growth, for which their EC50 values were up to 400 times greater. The disinfectant, hydroxyquinolene sulphate was highly effective at reducing germination but less effective against mycelial growth, with EC50 values of 0.002 and 8.5 mg l-1 respectively. The potential role of these fungicides for disease management in the nursery and vineyard is discussed. Marlene Jasper Copyright (c) 2001 Marlene Jasper Thu, 30 Jun 2022 11:29:14 +0000 Curative Treatments Trialed on Young Grapevines Infected with «Phaeomoniella chlamydospora» Internal symptoms of Petri disease include brown wood-streaking and an abnormally dark pith, caused by Phaeomoniella chlamydospora (Pch). This paper reports on the effect of eight fungicides and a hot water treatment on naturally infected one-year-old Pinot Noir rootlings in a glasshouse trial. Vines were destructively assessed 22 weeks after planting. All treatments significantly reduced the incidence of dark pith. Phosphonate treatment was the most effective and benzothiodiazole was the least effective treatment with respect to controlling Pch. These results will contribute to the development of an integrated management program for grapevine propagating material. Ian G. Pascoe, Jacqueline Edwards, Nam K. Nguyen, Natalie Laukart Copyright (c) 2001 Ian G. Pascoe, Jacqueline Edwards, Nam K. Nguyen, Natalie Laukart Thu, 30 Jun 2022 11:29:49 +0000 The Effect of Hot-Water Treatment on Fungi Occurring in Apparently Healthy Grapevine Cuttings <p>Many grapevine nurseries are presently employing a hot-water treatment for propagation material as a prophylactic measure. The aim of this study was thus to determine the efficacy of this treatment in eliminating fungal endophytes from grapevine cuttings. The number of fungal colonies isolated from the hot-water treated cuttings 6 months after planting were not, however, significantly different (P=0.05) from that of the untreated cuttings. This was in contrast to where isolations were made directly after treatment, when no known living fungal pathogens were found inside treated vine tissue. These results therefore indicate that the hot-water treatment is effective in eliminating the most well-known fungal pathogens and endophytes from grapevine tissue. Further research now needs to be focused on combining this treatment with biological control agents in an attempt to delay recolonisation of tissue by fungal pathogens.</p> Lizeth Swart, Pedro W. Crous, Sonja Coertze Copyright (c) 2001 Lizeth Swart, Pedro W. Crous, Sonja Coertze Thu, 30 Jun 2022 11:30:27 +0000 Effect of Hot Water Treatments on Eradication of «Phaeomoniella chlamydospora» and «Phaeoacremonium inflatipes» from Dmant Grapevine Wood Hot water treatments were applied to eradicate Phaeoacremonium inflatipes and Phaeomoniella chlamydospora from dormant grapevine wood. A thirty-minute hot water treatment at 51°C did not eliminate these pathogens from dormant wood cuttings. Cuttings first inoculated with Pa. chlamydospora or Pm. inflatipes or both fungi, and then subjected to a hot water treatment were either incubated in crispers, or planted for six to eight weeks. Vascular discoloration was scored followed by isolation from the cuttings onto potato dextrose agar amended with 0.1 g l-1 tetracycline (PDA-tet). Isolations confirmed the presence of the pathogens in the inoculated, hot-water treated cuttings as well as in the inoculated, untreated control cuttings. This finding, along with earlier research on the direct effect of hot water on the mycelium of these species, leads to the conclusion that hot water treatments are ineffective in eliminating vine decline pathogens from dormant wood. Suzanne Rooney, W. Douglas Gubler Copyright (c) 2001 Suzanne Rooney, W. Douglas Gubler Thu, 30 Jun 2022 11:31:41 +0000 Effects of «Trichoderma» Treatments on the Occurrence of Decline Pathogens in the Roots and Rootstocks of Nursery Grapevines The growth-stimulating attributes of Trichoderma treatments (dips, soil amendments and drenches with Trichoderma products containing propagules of selected strains of Trichoderma harzianum) in grapevine nurseries, and their effect on the occurrence of fungi in roots and rootstocks of nursery grapevines, in particular fungi causing Petri disease (Phaeomoniella chlamydospora and Phaeoacremonium spp.) and black foot rot (Cylindrocarpon spp.), were compared with quintozene/procymidone treated (standard) vines. Early shoot growth of Trichoderma treated vines was visibly better than that of the control vines. Eight months after planting, at uprooting, percentage take and shoot mass of Trichoderma and standard treated vines were similar, but total root mass was significantly higher for Trichoderma treated vines. Low percentages of Cylindrocarpon spp. were isolated from the rootstocks of treated and untreated vines, while less Petri disease fungi were isolated from rootstocks of Trichoderma treated vines. Markedly fewer fungi were also isolated from the roots of Trichoderma treated vines. Incidences of Petri disease fungi in roots of Trichoderma and standard treated vines were similar, but fewer Cylindrocarpon spp. were isolated from Trichoderma treated vines. These results indicate the potential of Trichoderma treatments in grapevine nurseries for the production of stronger vines with lower Phaeomoniella/Phaeoacremonium and Cylindrocarpon infection levels. Francois Halleen, Johann van der Vyver, Paul Fourie, Wouter Schreuder Copyright (c) 2001 Francois Halleen, Johann van der Vyver, Paul Fourie, Wouter Schreuder Thu, 30 Jun 2022 11:32:18 +0000 Preface Copyright (c) 2001 Thu, 30 Jun 2022 10:45:16 +0000 Towards Commoly Agreed Answers to Some Basic Questions on Esca The present paper focuses on some basic questions about what we still call esca, such as: What is esca? Is esca a complex of diseases including young esca, white rot and esca proper, while Pch causes decline on its own? Is the concept of microbial succession to be retained, and what is its exact meaning? Can Pch, Pal and Fop be considered primary pathogens? What should the decline associated with Pch (Pal, Pin?) be called? These and other questions will be commented. Giuseppe Surico Copyright (c) 2001 Giuseppe Surico Thu, 30 Jun 2022 11:33:51 +0000 Final Note on the General Discussion Copyright (c) 2001 Thu, 30 Jun 2022 11:34:21 +0000 Abstracts Copyright (c) 2001 Thu, 30 Jun 2022 11:33:20 +0000