First Report of Web Blight on Winter Savory (Satureja Montana "Repandens") Caused by Rhizoctonia solani AG-1-IA in Italy

Satureja montana L. (winter savory "Repandens") is an evergreen shrub. In late summer 2010, blight was observed on a farm near Albenga (northern Italy) on 3% of 500 potted 2-month-old plants. Semicircular, water-soaked lesions appeared first on stems then on leaves. As the disease progressed, blighted leaves turned brown, withered, clung to the shoots, and matted on the surrounding foliage within 5 to 6 days. Stem fragments taken from the margin of the diseased tissues of 10 plants were disinfected for 10 s in 1% NaOCl, rinsed with sterile water, and plated on potato dextrose agar (PDA) amended with 100 μg/liter streptomycin sulfate. A fungus with morphological characters of Rhizoctonia solani was consistently isolated. Three isolates of R. solani obtained from affected plants were successfully anastomosed with R. solani isolate AG 1 (ATCC 58946). Three pairings were made for each tested strain. Hyphal diameter at the point of anastomosis was reduced, the anastomosis point was obvious, and death of adjacent cells was observed. Results were consistent with other reports on anastomosis reactions (2). Isolates from winter savory were paired with R. solani isolates AG 2, 3, 4, 6, 7, or 11 and examined microscopically. Anastomosis was not observed in any of the pairings. Tests were repeated once. Mycelium of 10-day-old isolates from winter savory appeared light brown, compact, and radiate. Numerous, dark brown sclerotia, 1 to 4 mm in diameter (average 1.7), developed within 20 days after transfer of mycelia to PDA in 90-mm-diameter petri dishes and incubated (11-h daylight, 13-h dark) at 21 to 24°C. Descriptions of mycelium and sclerotia were typical for subgroup IA Type 2 (3). The internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS1/ITS4 and sequenced. BLASTn analysis (1) of the 696 bp showed a 99% homology with the sequence of R. solani. The nucleotide sequence has been assigned GenBank No. JQ313811. For pathogenicity tests, inoculum of R. solani was prepared by growing the pathogen on wheat kernels autoclaved in 1-liter glass flasks (30 min at 121°C and 1 atm) for 15 days. One of the isolates assigned to the anastomosis group AG 1 IA was tested. Five 90-day-old plants of S. montana were inoculated. Each plant grown in 2-liter pots in a steam disinfested peat/pumice/pine bark/clay mix (50:20:20:20:10) was inoculated with 10 g of infested wheat kernels placed at the base of the stem. Five plants inoculated with noninfested wheat kernels served as the control. Plants covered with plastic bags were arranged randomly in a growth chamber at 20 ± 1°C with 12-h light/dark for 5 days. Symptoms, similar to those observed in the farm, developed 4 days after inoculation. Ten colonies of R. solani were reisolated from infected leaves and stems of each inoculated plant. Control plants remained healthy. The pathogenicity test was carried out twice. Symptoms caused by R. solani have been recently observed on S. hortensis in Poland (4). This is, to our knowledge, the first report of blight of S. montana caused by R. solani in Italy. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) D. E. Carling. Rhizoctonia Species: Taxonomy, Molecular Biology, Ecology, Pathology and Disease Control. Kluwer Academic Publishers, The Netherlands, 1996. (3) R. T. Sherwood. Phytopathology 59:1924, 1969. (4) B. Zimowska. Herba Polonica 56:29, 2010.

First Report of Postharvest Fruit Rot in Avocado (Persea americana) Caused by Lasiodiplodia theobromae in Italy

Avocado (Persea americana Mill.) is grown in some areas of southern Italy. In spring 2011, a previously unknown rot was observed on fruit that was marketed in Torino (northern Italy). The decayed area started from the stalk, appeared irregular and soft, and was surrounded by a dark brown margin. The internal decayed area appeared rotten, brown, and surrounded by bleached tissue. Fragments (approximately 3 mm) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at temperatures between 21 and 25°C under alternating conditions of light and dark. Colonies of the fungus initially appeared whitish, later turning mouse gray to black. Mature mycelium was septate and produced a dark pigment. The fungus, grown on oat agar (2) and incubated at temperatures between 21 and 25°C under alternating light and darkness, produced grayish colonies with a fluffy aerial mycelium that became dark with age and produced black pigments. After 18 days of incubation, such colonies produced pycnidia aggregated into stromatic masses, emerging from decayed tissues, and up to 3 to 4 mm in diameter. Conidia produced in the pycnidia were initially unicellular, hyaline, granulose, ovoid to ellipsoidal, and measured 20.8 to 26.9 × 12.5 to 16.1 (average 24.4 × 13.5) μm. After 7 days, mature conidia became darker, uniseptate, and longitudinally striate. Paraphyses produced within the tissues of pycnidia were hyaline, cylindrical, nonseptate, and up to 63 μm long. Morphological characteristics of mycelia, pycnidia, and conidia observed with a light microscope permitted identify of the fungus as Lasiodiplodia theobromae (3). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (1) of the 488-bp segment showed a 100% similarity with the corresponding sequence (GenBank Accession No. GQ502453) of L. theobromae Pat. Griffon & Maubl. The nucleotide sequence of the strain used for pathogenicity tests was submitted to GenBank (Accession No. JN849098). Pathogenicity tests were performed by inoculating 10 avocado fruits after surface disinfesting in 1% sodium hypochlorite and then wounding. Mycelial disks (8 mm in diameter) obtained from PDA cultures of one strain were placed on wounds. Ten control fruits were inoculated with plain PDA. Fruits were incubated at 15 ± 1°C. The first symptoms developed 4 days after the artificial inoculation. After 7 days, the rot was evident and L. theobromae was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice. To our knowledge, this is the first report of the presence of L. theobromae causing postharvest fruit rot on avocado in Italy, as well as in Europe. The occurrence of postharvest fruit rot on avocado caused by L. theobromae was described in many avocado-producing areas such as the United States (4), South Africa, and Israel. In Italy, the economic importance of avocado cultivation is currently limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2). P. Narayanasamy. Microbial Plant Pathogens. Detection and Disease Diagnosis: Fungal Pathogens. Springer, Dordrecht, 2011. (3) E. Punithalingam. Sheet 519. CMI Description of Fungi and bacteria, 1976. (4) H. E. Stevens and R. B. Piper. Circular No. 582, USDA, 1941.

Golovinomyces biocellatus on Oregano (Origanum vulgare 'Compactum') in Italy

Origanum vulgare L., common name oregano, also known as pot marjoram, Lamiaceae family, is grown for its aromatic and medicinal properties and as an ornamental. In particular, O. vulgare 'Compactum' is becoming popular as a potted plant. During January 2011, 3-month-old plants grown on a commercial farm located near Albenga (northern Italy) showed signs and symptoms of an unknown powdery mildew. Ninety percent of the plants were affected. The adaxial leaf surfaces were covered with white mycelia and conidia, while the abaxial surfaces were less infected. As the disease progressed, infected leaves turned yellow, wilted, and eventually fell off. Mycelia were also observed on stems. Conidia were hyaline, elliptical, borne single or in short chains (three to four conidia per chain), and measured 37.9 × 19.6 (31.2 to 45.1 × 14.9 to 26.2) μm. Conidiophores were erect with a cylindrical foot cell measuring 81.1 × 9.7 (54.2 to 112.4 × 7.9 to 11.6) μm followed by two to three shorter cells measuring 26.8 × 11.8 (16.6 to 38.1 × 8.5 to 15.3) μm. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1F/ITS4 and sequenced (3) (GenBank Accession No. JN594608). The 560-bp amplicon had 99% homology with the sequence of Golovinomyces biocellatus (GenBank Accession No. AB307675). Pathogenicity was confirmed through inoculation by spraying a conidial suspension (6 × 10⁴ CFU/ml) prepared from diseased leaves onto leaves of healthy O. vulgare 'Compactum' plants. Four plants were inoculated while the same number of noninoculated plants served as a control. Plants were maintained in a glasshouse at temperatures ranging from 23 to 28°C. Ten days after inoculation, typical symptoms of powdery mildew developed on inoculated plants. The fungus observed on inoculated plants was morphologically identical to that originally observed. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. G. biocellatus on O. vulgare has been reported in Switzerland (2) and Argentina (4) and it is present on other plant genera in Italy. In Italy, on the same host, attacks of Erysiphe galeopsis have been previously reported (1). The economic importance of this disease is currently limited due to limited planting of this species. However, in the last years, potted aromatic plants represent a steady increasing crop in Italy. Voucher specimens are available at the Agroinnova Collection, University of Torino. References: (1) K. Amano. Host Range and Geographical Distribution of the Powdery Mildew Fungi. Japan Science Society Press, Tokyo, 1986. (2) A. Bolay. Cryptog. Helv. 20:1, 2005. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990. (4) S. M. Wolcan. J. Plant Patho. 91:501, 2009.

Powdery Mildew Caused by Golovinomyces orontii on Creeping Bellflower (Campanula rapunculoides) in Italy

Creeping (June) bellflower (Campanula rapunculoides) is an herbaceous plant belonging to the Campunalaceae family. It has showy flowers, which is very much appreciated for gardens and landscaping. During the summer of 2011, 6- to 9-month-old plants grown in a garden near Biella (northern Italy) showed signs and symptoms of an unknown powdery mildew. The adaxial leaf surfaces were covered with white mycelia and conidia, while the abaxial surfaces were less infected. As the disease progressed, infected leaves turned yellow and wilted. Mycelia were also observed on stems, petioles, and flower calyxes of inflorescences. Seventy percent of plants were diseased. Conidia were hyaline, elliptical to ovoid (sometimes doliform), borne in short chains (up to three conidia per chain), and measured 27 to 42 (34) × 16 to 24 (19) μm. Conidiophores were erect with a cylindrical foot cell measuring 64 to 105 (80) × 11 to 12 (11) μm and followed by two shorter cells measuring 17 to 24 (20) × 11 to 15 (13) μm. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1F/ITS4 and sequenced (3) (GenBank Accession No. JN639855). The 405-bp amplicon had 98% homology with the sequence of Golovinomyces orontii GQ183948. Pathogenicity was confirmed through inoculation by gently pressing diseased leaves onto leaves of healthy C. rapunculoides plants. Three plants were inoculated while the same number of noninoculated plants served as a control. Plants were maintained outside at temperatures from 10 to 26°C. Fifteen days after inoculation, symptoms and signs of powdery mildew developed on inoculated plants. The conidial morphology of the powdery mildew fungus that developed on inoculated plants was identical to the conidial morphology observed in the original fungus. Noninoculated plants remained healthy. The pathogenicity test was carried out twice. G. orontiii has been reported on C. rapunculoides in several eastern European countries as well as in Switzerland and Germany (1,2). To our knowledge, this is the first report of the disease in Italy. The economic importance of this disease is currently limited in Italy because of limited planting of this host. References: (1) A. Bolay. Cryptogam. Helv. 20:1, 2005. (2) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Stuttgart, Germany, 1995. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

Ochratoxigenic black species of Aspergilli in grape fruits of northern Italy identified by an improved PCR-RFLP procedure

A collection of 356 isolates of Aspergillus spp. collected during 2006 and 2007 from grapevines in northern Italy were identified through Internal Transcribed Spacer based Restriction Fragment Length Polymorphism (ITS-RFLP) and tested for ochratoxin A (OTA) production. Restriction endonuclease digestion of the ITS products using the endonucleases HhaI, HinfI and RsaI, distinguished five different RFLPs. From each pattern, three samples were sequenced and the nucleotide sequences showed different species corresponding to Aspergillus niger, A. carbonarius, A. tubingensis, A. japonicus and A. aculeatus. By comparing the sequences of the ITS regions, also the uniseriate species A. japonicus and A. aculeatus could be differentiated by HinfI digestion of the ITS products. Among the aspergilli, A. niger was the major species associated with grapes during 2006 (57.4%), while A. carbonarius was the major species during 2007 (46.6%). All the strains of Aspergillus were tested for their ability to produce OTA on Yeast extract sucrose medium (YES), as it was tested as an optimal substrate for the evaluation of OTA production by black aspergilli. Out of 356 isolates, 63 (17.7%) isolates produced OTA ranging from 0.05 to 3.0 µg mL(-1). Most of the ochratoxigenic isolates were A. carbonarius (46) in both years, but also some strains of A. tubingensis (11) and A. japonicus (6) produced lower amounts of OTA.

Effect of climate change on Alternaria leaf spot of rocket salad and black spot of basil under controlled environment

Plant responses to elevated CO2 and temperature have been much studied in recent years, but effects of climate change on pathological responses are still largely unknown. The pathosystems rocket (Eruca vesicaria subsp. sativa)--Alternaria leaf spot (Alternaria japonica) and basil (Ocimum basilicum)--black spot (Colletotrichum gloeosporioides) were chosen as models to assess the potential impact of increased CO2 and temperature on disease incidence and severity under controlled environment. Potted plants were grown in phytotrons under 4 different simulated climatic conditions: (1) standard temperature (ranging from 18 degrees to 22 degrees C) and standard CO2 concentration (400 ppm); (2) standard temperature and elevated CO2 concentration (800 ppm); (3) elevated temperature (ranging from 22 degrees to 26 degrees C, 4 degrees C higher than standard) and standard CO2 concentration; (4) elevated temperature and CO2 concentration. Each plant was inoculated with a spore suspension containing 1 x 10(5) cfu/ml of the pathogen. Disease incidence and severity were assessed 14 days after inoculation. Increasing CO2 to 800 ppm showed a clear increment in the percentage of Alternaria leaf spot on rocket leaves compared to standard conditions. Basil plants grown at 800 ppm of CO2 showed increased black spot symptoms compared to 400 ppm. Disease incidence and severity were always influenced by the combination of rising CO2 and increased temperature, compared to standard conditions (400 ppm of CO2 - 22 degrees C). Considering the rising concentrations of CO2 and global temperature, we can assume that this could increase the severity of Alternaria japonica on rocket and Colletotrichum gloeosporioides on basil.

Compost suppressiveness against Phytophthora spp. on Skimmia japonica and azalea

Suppression of soil-borne plant diseases with composts has been widely studied. Composts have been found to be suppressive against several soil-borne pathogens in various cropping systems. Ornamental plants are generally cultivated in pots, allowing the use of suppressive substrates to control zoospore-producing pathogens, like Phytophthora sp. The objective of the present work was to assess compost suppressiveness against Phytophthora cinnamomi on Rhododendron spp., and against Phytophthora nicotianae, an emerging pathogen on Skimmia japonica. A municipal compost that showed a good suppressive activity in previous trials on vegetable crops was used. Compost was mixed at 10, 20 e 40% (v/v) with a commercial peat substrate, used as control. Substrates have been inoculated at 1g/l dosage of wheat and hemp kernels of Phytophthora spp. and after one week 15-20 plants were transplanted for each treatment in 2 liters volume pots and placed in greenhouse at 20 degrees C. A chemical control (Metalaxil-M) was also used. Diseased plants were assessed weekly after transplanting and above-ground biomass of plants was assessed at the end of the trials. Results showed a significant disease control when compost was used at 20-40% on S. japonica, without showing any phytotoxic effect. Disease suppression was shown at 40% on azalea, but compost was slightly phytotoxic on plants. The use of compost based substrates can be a suitable strategy for controlling soil-borne diseases on ornamentals, but results depend also on alkalinity tolerance of plants.

Effects of silicates from scaps of photovoltaic industries on powdery mildew of zucchini

Silicon is the second most abundant element on earth's surface and its use can stimulate natural defense mechanisms in plants. The effect of silicate from scraps of photovoltaic industries against powdery mildew on zucchini (Cucurbita pepo) was evaluated under greenhouse conditions. Potted plants were inoculated with a spore suspension containing 1 x 10(5) cfu/ml. The following treatments have been carried out, 3 and 10 days after pathogen inoculation: chemical fungicide (propiconazole, TILT 25 EC, Syngenta); Bacillus subtilis (250 g/hl, Serenade, Intrachem); 1% and 0.1% sodium silicate (r = 1); 1% and 0.1% sodium silicate (r = 2); tap water as control. Disease incidence and severity were assessed 7, 14 and 21days after pathogen inoculation. Results showed that the application of 1% sodium silicate (r = 1) significantly reduced the powdery mildew to a level similar to chemical control. The other treatments, including Bacillus subtilis, reduced disease severity compared to water control, but were less efficient. The use of silicates from photovoltaic industries is a valid alternative for the control of powdery mildew on zucchini, in particular in organic farming. However, silicates might not be sufficient at higher disease incidence levels, and their use is more suitable within an integrated disease control strategy.

First Report of Sclerotinia Blight Caused by Sclerotinia sclerotiorum on Fan Columbine (Aquilegia flabellata) in Italy

Fan columbine is a perennial garden species belonging to the family Ranunculaceae. During the spring of 2011, extensive wilting was observed on 5-month-old potted plants of Aquilegia flabellata grown in an experimental glasshouse belonging to the Center AGROINNOVA at Grugliasco (northern Italy). First symptoms included stem necrosis and darkening and withering of leaves. Plant wilt occurred a few days after the appearance of the first symptoms. Infected plants were characterized by the presence of soft, watery tissues. In the presence of high relative humidity, lesions became covered with a whitish mycelium and irregular, dark gray sclerotia (1.5 to 4.0 × 1.0 to 2.8, average 2.8 × 2.1 mm) were produced on the mycelium. Diseased tissue was surface sterilized for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/l of streptomycin sulfate. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently recovered from infected stem pieces. Sclerotia produced on PDA measured 2.0 to 7.0 × 2.0 to 5.0 (average 4.2 × 2.9) mm. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1F/ITS4 and sequenced. BLAST analysis (1) of the 575-bp segment showed a 100% homology with the sequence of S. sclerotiorum (EF091809). The nucleotide sequence has been assigned the GenBank Accession No. JN013184. Pathogenicity of one isolate obtained from sclerotia of infected plants was confirmed by inoculating three 6-month-old plants transplanted in 16-cm-diameter pots in a glasshouse in a sphagnum peat/pomix/pine bark/clay (50:20:20:10) mix. Inoculum that consisted of 3 g/l of substrate of sterile wheat kernels infested with mycelium and sclerotia was placed in the soil and around the base of each plant. Three noninoculated plants served as controls. Plants were maintained in a growth chamber at 21 ± 1°C and relative humidity >90%. The inoculation trial was carried out twice. All inoculated plants developed leaf yellowing within 15 days of soil infestation. White, cottony mycelium and dark sclerotia developed on stems and at the base of all inoculated plants. Eventually, infected plants wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from the stems of inoculated plants. To our knowledge, this is the first report of S. sclerotiorum on A. flabellata in Italy. The disease has been previously reported on A. vulgaris in the United States (3) and A. glandulosa in Russia (4). The economic importance of this disease in Italy is currently limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) N. F. Buchwald. Kgl. Veterisk Landb. Aarssk. 75, 1949. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrived from http://nt.ars-grin.gov/fungaldatabases/ , July 7, 2011. (4) P. M. Zhiboedov et al. Mikol. Fitopatol, 36:48, 2002.

First Report of Black Rot Caused by Phomopsis cucurbitae on Cantaloupe (Cucumis melo) in the Piedmont Region of Northern Italy

Cucumis melo L., belonging to the Cucurbitaceae family, is cultivated on more than 23,000 ha in Italy. Cantaloupe (C. melo L. var. cantalupensis Naudin) is the most popular variety. In summer 2010, a previously unknown rot was observed on fruits produced in Italy and marketed in the Piedmont Region of northern Italy. Early symptoms on fruit consisted of irregular, brown, soft, sunken lesions up to 10 cm in diameter. No surface mold was visible and pycnidia were not present. Internally, the decay is adjacent to the sunken area of the fruit's surface and is soft, water soaked, spongy, with a nearly circular margin, and easily separated from healthy tissues. Fragments (approximately 3 mm³) were taken from the margin of the internal diseased tissues, cultured on potato dextrose agar (PDA), and incubated at 24 ± 1°C, (16 h of light and 8 h of darkness). Fungal colonies initially appeared coarse, at first whitish then buff brown, and produced dark pycnidia 0.5 mm in diameter, which exuded numerous conidia belonging to two types. Type A conidia were hyaline, unicellular, ellipsoidal to fusiform, sometimes slightly constricted in the middle, and measured 5.6 to 10.3 × 1.7 to 2.6 (average 8.0 × 2.1) μm. Type B conidia were hyaline, long, slender, curved, and measured 17.1 to 26.6 × 0.7 to 1.4 (average 22.0 × 1.0) μm. Sclerotia were not produced. The morphological characteristics of the fungus corresponded to those of the genus Phomopsis (1). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis of the 543-bp segment showed a 99% similarity with the sequence of a Phomopsis sp. (GenBank Accession No. HM999947). The nucleotide sequence has been assigned the GenBank Accession No. JN032733. Both Phomopsis cucurbitae and P. sclerotioides are pathogenic to Cucurbitaceae, however P. cucurbitae is identifiable by the production of B conidia and the absence of sclerotia. Therefore, P. cucurbitae has been considered the causal agent of the disease. Pathogenicity tests were performed by inoculating three wounded cantaloupe fruits after surface disinfesting in 1% sodium hypochlorite. Six wounds per fruit, 1 cm deep, were made with a sterile needle. Mycelial disks (10 mm in diameter), obtained from PDA cultures of one strain, were placed on each wound. Three control fruits were inoculated with PDA. Fruits were incubated at 16 ± 1°C in the dark. The first symptoms developed 4 days after the artificial inoculation. Two days later, the rot developed at all inoculation points and the pathogen was consistently reisolated. Noninoculated fruit remained healthy. The pathogenicity test was performed twice with similar results. P. cucurbitae has been reported on melon in many countries (2,3). To our knowledge, this is the first report of the disease in Italy. Currently, the relevance of the disease in the country is not yet well known. However, attention must be paid considering that the pathogen can be transmitted through seeds. References: (1) H. L. Barnett and B. B. Hunter. Illustrated Genera of Imperfect Fungi. Burgess Publishing Company, Minneapolis, MN, 1972. (2) L. Beraha and M. J. O'Brien. Phytopathol. Z. 94:199, 1979. (3) E. Punithalingam and P. Holliday. Phomopsis cucurbitae. IMI Descriptions of Fungi and Bacteria. 47, Sheet 469, 1975.

First Report of Leaf Spot of Wild (Diplotaxis tenuifolia) and Cultivated (Eruca vesicaria) Rocket Caused by Alternaria japonica in Italy

Wild (Diplotaxis tenuifolia) and cultivated (Eruca vesicaria) rocket, popular crops in Italy as well as in many Mediterranean areas, are grown for fresh consumption as well as for dish decoration. During fall and winter of 2010 to 2011, extensive necroses were observed on leaves of D. tenuifolia and E. vesicaria that were grown in commercial greenhouses in Piedmont and Liguria (northern Italy). The disease affected 30 to 40% of 60-day-old plants. First symptoms were usually black-brown lesions, 1 to 30 mm in diameter, which progressively turned black. Lesions usually started on the upper side of older leaves at the leaf margins and tips and developed a yellow halo. Eventually, lesions also affected leaf veins and stems. A fungus was consistently isolated from infected leaves on potato dextrose agar and was grown on water agar (15 g/liter) amended with autoclaved rocket tissues (100 g/liter). After 12 days of growth at 22°C and 12-h dark/12-h light, conidia that were produced were dark brown, obclavate, obpyriform, ovoid or ellipsoid, with beaks. Round conidia without beaks were also present. Conidia showed two to seven (average three to four) transverse and one to three longitudinal septa, and measured 17.7 to 56.2 (average 30.9) × 6.6 to 17.8 (average 10.8) μm. Conidia were produced singly or in short chains (two to three elements) and mostly presented a conical or cylindrical beak, 1.8 to 7.3 (average 3.6) μm, pale light brown to brown. On the basis of its morphological characteristics, the pathogen was identified as an Alternaria sp. (3). DNA was extracted with Terra PCR Direct Polymerase Mix (Clontech, Mountain View, CA) and PCR was carried out with ITS 1/ ITS 4 primer (4). A 553-bp PCR product was sequenced and a BLASTn search (1) confirmed that the sequence corresponded to Alternaria japonica. The nucleotide sequence has been assigned the GenBank Accession No. JP 742643. Pathogenicity tests were performed by spraying leaves of healthy 30-day-old wild and cultivated rocket plants with an aqueous 1 × 10⁵ spore/ml suspension. The inoculum was obtained from cultures of the fungus grown on sterilized host leaves placed on water agar for 20 days in light/dark at 22 ± 1°C. Plants sprayed only with water served as controls. Three pots (four plants per pot) were used for each treatment. Plants were covered with plastic bags for 4 days after inoculation and maintained in a glasshouse at 22 ± 1°C. Lesions developed on leaves 7 days after inoculation with the spore suspension, whereas control plants remained healthy. A. japonica was consistently reisolated from these lesions. The pathogenicity test was carried out twice. The presence of A. japonica has been reported on several brassica hosts, such as Brassica napus, B. nigra, B. oleracea, and B. rapa (2). This is, to our knowledge, the first report of A. japonica on wild and cultivated rocket in Italy as well as in Europe. Because of the importance of rocket in many countries, the potential impact of this disease is high. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) J. C. David, IMI Description of Fungi and Bacteria. 144:1432, 2000. (3) E. G. Simmons. Alternaria. An Identification Manual. CBS Biodiversity Series 6, Utrecht, The Netherlands, 2007. (4) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Leaf Spot of Rocket (Eruca sativa) Caused by Fusarium equiseti in Italy

During the summer of 2010, rocket (Eruca sativa) plants grown in an open field and under a plastic tunnel in Piedmont (northern Italy) showed symptoms of a previously reported foliar disease. Symptoms were observed on 30-day-old plants and consisted of small, circular, brown leaf spots (1 to 3 to 10 to 12 mm in diameter), sometimes later becoming elliptical. Necrotic lesions were cracked in the center and showed a well-defined border, frequently surrounded by a violet-brown halo. Approximately 40% of the plants were affected with 30 to 40% of the leaves infected. An orange-brown colony with characteristics of Fusarium was isolated from leaf tissues of 30 infected plants on potato dextrose agar (PDA). Isolates were purified, subcultured on PDA, and single-spore cultures were obtained. On PDA, they produced orange-brown colonies and purple pigments. On Spezieller Nährstoffarmer agar (SNA) (1), the isolates produced hyaline macroconidia with dorsiventral curvature, five to seven septate, and measuring 36.2 to 49.3 × 3.4 to 5.3 (average 41.9 × 4.0) μm. Chlamydospores, solitary but also in short chains (two to three elements), measuring 7.2 to 15.3 (average 10.1) μm were produced on carnation leaf agar (CLA) after 10 days and became verrucose 20 days later. Macroconidia were produced on CLA in orange sporodochia from monophialides on branched conidiophores. Microconidia were not observed. Such characteristics are typical of the genus Fusarium (1). The rDNA ITS region (internal transcribed spacer) was amplified using the primers ITS1/ITS4 (2) and sequenced. BLASTn analysis of the 480-bp product obtained showed an E-value of 0.0 with Fusarium equiseti. The nucleotide sequence has been assigned the GenBank Accession No. JF460797. The translation elongation factor-1α (EF-1α) gene (GenBank Accession No. JN127347) was amplified using primers EF-1/EF-2 and sequenced. The 702-bp fragment showed 99% identity with F. equiseti (GenBank Accession No. FJ939673.1). To confirm pathogenicity, 20-day-old rocket plants were transplanted into 2-liter volume pots, filled with a steamed peat/perlite/sand (60:20:20 vol/vol) substrate and maintained in a growth chamber at 25 ± 1°C. Five pots per treatment were used, each pot containing two plants. The artificial inoculation was carried out either by spraying leaves with a spore suspension prepared from 15-day-old cultures of the pathogen on PDA or by applying CLA agar disks (6 mm in diameter) from 10-day-old cultures onto leaves. Control plants were inoculated with distilled water or with noninoculated agar disks. Plants were covered with plastic bags for 5 days. The first symptoms, consisting of chlorotic leaf halo and leaf spots surrounded by a violet-brown halo, developed 15 days after inoculation by foliar spraying and 5 days after inoculation by disks. Noninoculated plants remained healthy. F. equiseti was consistently isolated from symptomatic plants. The pathogenicity test was conducted twice. To our knowledge, this is the first report of F. equiseti on E. sativa in Italy. Currently, this disease is present in several farms in northern Italy. Its importance might increase because of the widespread cultivation of cultivated rocket in Italy. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell, Ames, IA, 2006. (2) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Fusarium oxysporum Causing Wilt on Jade Plant (Crassula ovata) in Italy

During summer 2010, symptoms of a wilt disease were observed in a commercial farm in northern Italy on Crassula ovata (jade plant). First symptoms consisted of chlorosis and premature drop of still turgid leaves. As the disease progressed, leaves turned yellow and wilted before dropping off and the stem wilted, bent, and eventually rotted starting from the base. In some cases, the stem broke or the basal portion of the leaf rotted. Brown discolorations were observed in the vascular system. Of 10,000 plants, 65% (cv. Mini) and 5% of 600 plants (cv. Magical Tree) were affected. Premature dropping of leaves was more frequent on cv. Magical Tree. Using the Komada's Fusarium-selective medium, a fungus was consistently and readily isolated from symptomatic vascular tissues of plants belonging to both cultivars. Isolates obtained from both cultivars were purified, subcultured on potato dextrose agar (PDA), and single-spore cultures were obtained. On PDA, both isolates produced pale violet, abundant, aerial mycelium, felted in old cultures, with purple pigments in the agar. The isolates were grown on Spezieller Nährstoffarmer agar for characterization of macroconidia and microconidia (1). Both isolates produced sparse, 3 to 5 septate, nearly straight macroconidia measuring 30 to 56 × 3 to 5 (average 40 × 4) μm with a short apical cell and a foot-shaped basal cell. Sporodochia were not observed. Unicellular, oval-elliptical microconidia measuring 5 to 13 × 3 to 4 (average 8 × 3) μm were produced on short monophialides. Chlamydospores were abundant, single and sometime in pairs, terminal and intercalary, rough walled, and measured 6 to 9 μm. Such characteristics are typical of Fusarium oxysporum (3). The ITS region (internal transcribed spacer) of rDNA was amplified with primers ITS1/ITS4 (4) and sequenced. BLASTn analysis of an isolate from C. ovata cv. Mini (515 bp, Accession No. HQ682196) and C. ovata cv. Magical Tree (509 bp, Accession No. HQ682197) showed an E-value of 0.0 with F. oxysporum. For these sequences, pairwise alignment of EMBOSS (E.B.I. - The European Bioinformatics Institute) revealed identity and similarity of 99.0%. To confirm pathogenicity, tests were conducted on 5-month-old plants of cvs. Mini and Magical Tree. Plants (three per treatment) were inoculated by dipping roots in a 1 × 10⁶ CFU/ml conidial suspension of the two isolates of F. oxysporum prepared from 10-day-old cultures grown on casein liquid medium (2), shaken (90 rpm) for 10 days at 24°C ± 1 (12-h fluorescent light, 12-h dark). Inoculated plants were transplanted into pots filled with steamed mix (sphagnum peat/perlite/pine bark/clay; 50:20:20:10) and maintained in a plant growth chamber at 25 ± 1°C under a regimen of 12 h per day of fluorescent light. Inoculated plants belonging to both cultivars showed typical first symptoms of Fusarium wilt after 13 days. In the following days, leaves dropped, stems wilted, and plants died. Noninoculated plants remained healthy. F. oxysporum was reisolated from inoculated plants. The pathogenicity test was conducted twice. This is, to our knowledge, the first report of F. oxysporum on C. ovata in Italy or worldwide. References: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Professional, Ames, IA, 2006. (2) A. Minuto et al. Phytoparasitica 36:294, 2008. (3) B. A. Summerell et al. Plant Dis. 87:117, 2003. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Basal Stem Rot of Apple Cactus (Cereus peruvianus monstruosus) Caused by Fusarium oxysporum in Italy

During the summer of 2010, 20% of 7,000 4-month-old plants of apple cactus (Cereus peruvianus monstruosus) showed symptoms of a basal stem rot in a commercial nursery located in Liguria (northern Italy). Affected plants showed yellow orange-to-pale brown color from the crown level to the stem apex and a water-soaked rot was observed on the stem starting from the base. Brown discoloration was observed in the vascular system. Eventually stems bent, plants collapsed and died, and affected tissues dried out. A Fusarium sp. was consistently and readily isolated from symptomatic tissue on Komada selective medium. Isolates were purified and subcultured on potato dextrose agar (PDA). Single-spore cultures on PDA, Spezieller Nährstoffarmer agar (SNA) (3), and carnation leaf-piece agar (CLA) (2) were incubated at 26 ± 1°C (12-h fluorescent light, 12-h dark). On PDA, cultures produced a thick growth of white-to-pink mycelium and pale pink pigments in the agar. On SNA, cultures produced short monophialides with unicellular, ovoid-elliptical microconidia measuring 4.3 to 8.2 × 2.3 to 3.8 (average 6.0 × 2.8) μm. Chlamydospores were abundant, single or paired, terminal and intercalary, rough walled, and 6 to 8 μm in diameter. On CLA, cultures produced orange sporodochia with macroconidia that were 3 to 4 septate, nearly straight with a foot-shaped basal cell and a short apical cell, and measured 31.1 to 51.5 × 4.4 to 3.5 (average 43.2 × 3.8) μm. Such characteristics are typical of Fusarium oxysporum (3). Amplification of the ITS (internal transcribed spacer) of the rDNA using primers ITS1/ITS4 (4) yielded a 498-bp band. Sequencing and BLASTn analysis of this band showed an E-value of 0.0 with F. oxysporum. The nucleotide sequence has been assigned GenBank Accession No. JF422071. To confirm pathogenicity, five 6-month-old healthy plants of C. peruvianus monstruosus were inoculated by dipping roots in a conidial suspension (2.4 × 10⁶ CFU/ml) of F. oxysporum isolated from affected plants. Inoculum was obtained from pure cultures of three single-spore isolates grown for 10 days on casein hydrolysate liquid medium. Roots were not wounded before the inoculation. Plants were transplanted into pots filled with steam-sterilized substrate (sphagnum peat/perlite/pine bark/clay 50:20:20:10). Five noninoculated plants served as a control. Plants were placed in a climatic chamber at 25 ± 1°C (12-h fluorescent light, 12 h-dark). Basal stem rot and vascular discoloration in the crown and stem developed within 30 days on each inoculated plant. Noninoculated plants remained healthy. F. oxysporum was consistently isolated from symptomatic plants. The pathogenicity test was conducted twice. F. oxysporum has been reported on Cereus spp. in the United States (1). To our knowledge, this is the first report of F. oxysporum on C. peruvianus monstruosus in Italy as well as in Europe. Currently, this disease is present in a few nurseries in Liguria. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St Paul, MN, 1989. (2) N. L. Fisher et al. Phytopathology 72:151, 1982. (3) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell, Ames, IA, 2006. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

First Report of Leaf Spot of Fan Columbine (Aquilegia flabellata) Caused by Phoma aquilegiicola in Italy

Aquilegia flabellata (Ranunculaceae), fan columbine, is a perennial herbaceous plant with brilliant blue-purple flowers with white petal tips that is largely present in gardens. It can also be grown for cut flower production. In September of 2008 and 2009, in a private garden located near Biella (northern Italy), a leaf blight was observed. Leaves of infected plants showed extensive, irregular, brown, necrotic lesions, which were slightly sunken with a well-defined border and surrounded by a violet-brown halo. A hole frequently appeared in the center of dried tissues. Lesions, initially measuring 0.5 mm, later expanded up to 15 mm in diameter and eventually coalesced to cover the entire leaf, which curled without falling. At a later stage, stems were also affected, causing death of the apical part of the plant. The disease affected 90% of the plants in the garden. Dark brown, subglobose pycnidia, 116 to 145 μm, containing light gray, ellipsoid, nonseptate conidia measuring 9.0 to 16.2 × 2.6 to 4.2 (average 12.7 × 3.4) μm were observed on symptomatic tissue. On the basis of these morphological characteristics, the fungus was related to the genus Phoma (2). Diseased tissue was excised from the margin of lesions, rinsed in sterile distilled water, and then cultured on potato dextrose agar (PDA) medium at 23 ± 1°C under alternating daylight and darkness (12-h light and 12-h dark). Fungal colonies produced a pale olive green, lightly floccose mycelium, generating clusters of dark olive green swollen cells. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 504-bp segment showed 100% homology with a sequence of Phoma aquilegiicola (GenBank Accession No. GU237735). The nucleotide sequence of our isolate was assigned GenBank Accession No. HM222537. Pathogenicity tests were performed by spraying a mycelium suspension of a homogenate of mycelium (1 × 10⁵ mycelial fragments per ml) obtained from 15-day-old PDA cultures of the fungus on leaves of six healthy 6-month-old potted A. flabellata plants. Six plants inoculated with a homogenate of PDA served as controls. Plants were maintained in a greenhouse in a high humidity chamber for 7 days after inoculation at 23 ± 1°C and under high relative humidity conditions (70 to 90%). The first foliar lesions developed on leaves 4 days after inoculation. After 15 days, 80% of the leaves were severely infected. Control plants remained healthy. The organism reisolated on PDA from leaf lesions was identical in morphology to the isolate used for inoculation. The pathogenicity test was carried out twice. To our knowledge, this is the first report of the presence of P. aquilegiicola on A. flabellata in Italy. Ascochyta aquilegiae (synonym P. aquilegiicola) has been reported on A. vulgaris in Germany (4) and Aquilegia spp. in the United States (3). Currently, the economic importance of this disease is limited, but may become a more significant problem if the use of A. flabellata in gardens increases. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) G. H. Boerema et al. Phoma Identification Manual. Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing, Wallingford, UK, 2004. (3) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (4) R. Laubert. Gartenwelt 34:621, 1930.

First Report of Verticillium Wilt Caused by Verticillium dahliae on Coleus verschaffeltii in Italy

Coleus verschaffeltii Lem. (synonym C. blumei Benth., Plectranthus scutellaroides (L.) R. Br., and Solenostemon scutellarioides (L.) Codd), a perennial plant belonging to the Lamiaceae family, is used as a bedding plant for public gardens. The most popular cultivars produce speckled leaves of various colors. In October 2010, severe outbreaks of a previously unknown wilt were observed in a public garden at Torino (northern Italy) on 50 8-month-old plants. Plants were sprinkle irrigated. Initial symptoms were withering of leaves starting from the collar and brown streaks in the vascular tissue of roots, crown, and stem. Subsequently, infected tissues wilted and plants became stunted. Early leaf drop was observed and plants appeared bare, keeping few leaves only at the end of stems. Infected plants did not die but they lost the original ornamental aspect. Seventy percent of the plants were affected. Stems of 10 plants were disinfected with 1% sodium hypochlorite. Cross-sections through symptomatic vascular tissues were plated on potato dextrose agar amended with 25 ppm of streptomycin sulfate. After 10 days at 20 to 23°C, a fungus was consistently recovered from 90% of stems. Irregular, black microsclerotia, 29 to 76 × 14 to 52 (average 49 × 28) μm, developed in hyaline hyphae after 15 days of growth. Hyaline, elliptical, single-celled conidia, 3.9 to 7.2 × 1.7 to 2.8 (average 5.1 × 2.2) μm, developed on verticillate conidiophores with three phialides at each node. On the basis of these morphological characteristics, the fungus was identified as Verticillium dahliae (3). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 (4) and sequenced. BLASTn analysis (1) of the 491-bp segment showed a 99% homology with the sequence of V. dahliae (Accession No. GU461634). The ITS nucleotide sequence of our isolate has been assigned the GenBank Accession No. JF704205. Pathogenicity tests were performed twice using 45-day-old plants obtained from seeds of C. verschaffeltii grown in 1-liter pots containing a 50:20:20:10 steamed mix of peat moss/pumice/pine bark/clay. Roots of 10 healthy plants were immersed in a conidial suspension (1.7 × 10⁷ ml^-1) of one culture of V. dahliae isolated from infected plants. Ten plants immersed in sterile water served as controls. Plants were maintained in a glasshouse at daily average temperatures between 20 and 28°C and relative humidity between 50 and 80%. First wilt symptoms and vascular discoloration in the roots, crown, and stems developed 20 days after inoculation. V. dahliae was consistently reisolated from infected vascular tissues of crown and stems of symptomatic plants. Noninoculated plants remained healthy. To our knowledge, this is the first report of Verticillium wilt on C. verschaffeltii in Italy. Verticillium wilt had been previously reported on S. scutellaroides in the United States (2). At this time, the economic importance of Verticillium wilt on C. verschaffeltii in Italy is limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) D. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society. St Paul, MN, 1989. (3) G. F. Pegg and B. L. Brady. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

First Report of Septoria Spot of Clementine Caused by Septoria citri in Italy

In January 2010, a fruit spot of "Clementine" (Citrus clementina Hort. ex Tan.) was observed on Italian-grown fruit in a market in northern Italy. The surface of the peel of infected fruits had black, irregular, necrotic areas that were slightly depressed, 10 mm in diameter, and surrounded by chlorotic halos. No pycnidia were observed on the necrotic spots. Tissues beneath the necrotic spots, which included the albedo (white pith), appeared dark and a black rot affected the external part of the juice vesicles. Small sections (approximately 3 mm²) of infected internal tissues were cultured on potato dextrose agar (PDA) amended with 25 ppm of streptomycin and maintained at 22 to 24°C. A slow-growing fungus with dark colored mycelium that produced pycnidia was consistently isolated. Conidia were hyaline, elongate, straight or slightly curved, unicellular, but sometimes with one septum, and measured 9.0 to 25.4 × 1.0 to 2.7 (average 17.7 × 1.8) μm. Preliminary morphological identification of the fungal isolates resembling Septoria spp. was confirmed by PCR using genomic DNA extracted from the mycelia of pure cultures. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLAST analysis of the 508-bp segment showed a 99% homology with the sequence of Septoria citri (GenBank Accession No. DQ897650). The nucleotide sequence has been assigned the GenBank Accession No. HQ176410. Pathogenicity of one isolate was tested by inoculating 10 fruits. These were wounded at the equatorial level (three wounds per fruit, 5 mm depth) and dipped for 10 s in a conidial suspension (1.2 × 10⁷ conidia/ml). Ten wounded noninoculated fruits were dipped in sterilized water and served as control. Fruits were kept at 10 ± 1°C. After 50 days, dark, sunken necrosis appeared around the wounds of inoculated fruits and the same symptoms first observed were present into the tissues beneath the wounds. S. citri was consistently reisolated from the inoculated fruits. Noninoculated fruits remained healthy. The pathogenicity test was carried out twice. The same disease was observed on other fruits belonging to the Rutaceae family, such as lemon in Greece (3) and on orange and lemon in Australia (1). In Italy, S. citri has been reported on lemon (2) fruit. To our knowledge, this is the first report of the presence of this pathogen on clementine in Italy as well in the world. The presence of Septoria spot on clementine fruits is currently sporadic in Italy; however it is necessary to monitor the incidence of this disease with field and postharvest surveys. References: (1) T. G. B. Osborn and G. Samuel. Trans. R. Soc. Aust. 46:166, 1922. (2) P. Petri. Boll. Stn. Patol. Veg. Roma N.S. 16:1, 1936. (3) D. G. Zachos. FAO Plant Prot. Bull. 6:41, 1957.

Fusarium oxysporum and its bacterial consortium promote lettuce growth and expansin A5 gene expression through microbial volatile organic compound (MVOC) emission

Fusarium oxysporum MSA 35 [wild-type (WT) strain] is a nonpathogenic Fusarium strain, which exhibits antagonistic activity to plant pathogenic F. oxysporum isolates. The fungus lives in association with a consortium of ectosymbiotic bacteria. The WT strain, when cured of the bacterial symbionts [the cured (CU) form], is pathogenic, causing wilt symptoms similar to those of pathogenic F. oxysporum f. sp. lactucae. Both WT and CU MSA 35 strains produce microbial volatile organic compounds (MVOCs), but with a different spectrum. In vitro dual culture assays were used to assess the effects of the MVOCs produced by WT and CU strains of F. oxysporum MSA 35 on the growth and expansin gene expression of lettuce seedlings. An increase in the root length (95.6%), shoot length (75.0%) and fresh weight (85.8%) was observed only after WT strain MVOCs exposure. Leaf chlorophyll content was significantly enhanced (68%) in WT strain MVOC-treated seedlings as compared with CU strain volatiles and nontreated controls. β-Caryophyllene was found to be one of the volatiles released by WT MSA 35 responsible for the plant growth promotion effect. Semi-quantitative and quantitative reverse transcription-PCR assays indicated a significant difference in the expansin gene expression level between leaf (6.7-fold) and roots (4.4-fold) exposed to WT strain volatiles when compared with the CU strain volatiles and those that were nonexposed.

First Report of Fusarium Wilt of Chicory (Cichorium intybus) Caused by Fusarium oxysporum in Italy

In the summer of 2009, a wilt of chicory was observed on 25 to 30% of 30-day-old Cichorium intybus L. cv. Clio plants grown outdoors on a commercial farm in Piedmont (northern Italy). Affected plants were chlorotic and stunted with poorly developed root systems compared with healthy plants. Black streaks were observed in the stem and proximal part of the leaf vascular system in wilted plants. Fusarium oxysporum Schltdl. was isolated from symptomatic vascular tissue on a Fusarium-selective medium (1) from 80% of samples. Grown on potato dextrose agar (PDA) for 4 days at 23°C, the colonies, initially white and later pale pink, produced hyaline microconidia that were oval-elliptical and cylindrical in shape measuring 5.6 to 14.9 (average 10.2) × 2.1 to 4.5 (3.0) μm, borne on short monophialides measuring 8.2 to 16.1 (average 13.2) × 2.1 to 4.2 (3.3) μm. Macroconidia were slightly curved, three-septate, with a slightly hooked apical cell and a foot-shaped basal cell measuring 24.9 to 41.6 (average 32.2) × 3.2 to 5.2 (4.3) μm. Chlamydospores were both terminally and intercalary, solitary but also in short chains (2 to 4 elements) measuring 21.1 to 41.0 (average 27.2) μm (2). The internal transcribed spacer (ITS) rDNA region was amplified using the primers ITS1/ITS4 and sequenced. BLASTn analysis of the 527-bp amplicon (GenBank Accession No. HQ644423) obtained had 98% sequence identity with F. oxysporum (GenBank Accession No. FJ605247). The translation elongation factor-1α (EF-1α) gene was amplified using primers EF-1/EF-2 and sequenced (GenBank Accession No. GU564259). The 663-bp fragment had 99% sequence identity with F. oxysporum (GenBank Accession Nos. EU313540, EU313539, and DQ837696). Pathogenicity tests were conducted on 15-day-old chicory plants from two cultivars (Clio and Katia). Thirty-five plants per cultivar were inoculated by dipping their roots in a 1 × 10⁶ CFU/ml suspension of isolate FusCic45B recovered from wilted chicory. Inoculated and noninoculated plants were transplanted into five pots filled with 10 liters of steamed mix (peat/perlite/sand, 60:20:20 vol/vol) and were maintained in a glasshouse at 25 to 27°C. Wilt symptoms and vascular discoloration of the roots, crown, and veins developed 15 days after inoculation on all inoculated plants. Plants of cv. Clio were more susceptible. F. oxysporum was always reisolated from infected plants using the Fusarium-selective medium. All noninoculated plants remained healthy. The pathogenicity test was conducted twice. To our knowledge, this is the first report of wilt caused by F. oxysporum on chicory, C. intybus, in Italy as well as worldwide. References: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (2) E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. The Pennsylvania State University Press, University Park, 1983.

A proteomics approach to study synergistic and antagonistic interactions of the fungal-bacterial consortium Fusarium oxysporum wild-type MSA 35

Fusarium oxysporum is an important plant pathogen that causes severe damage of many economically important crop species. Various microorganisms have been shown to inhibit this soil-borne plant pathogen, including non-pathogenic F. oxysporum strains. In this study, F. oxysporum wild-type (WT) MSA 35, a biocontrol multispecies consortium that consists of a fungus and numerous rhizobacteria mainly belonging to gamma-proteobacteria, was analyzed by two complementary metaproteomic approaches (2-DE combined with MALDI-Tof/Tof MS and 1-D PAGE combined with LC-ESI-MS/MS) to identify fungal or bacterial factors potentially involved in antagonistic or synergistic interactions between the consortium members. Moreover, the proteome profiles of F. oxysporum WT MSA 35 and its cured counter-part CU MSA 35 (WT treated with antibiotics) were compared with unravel the bacterial impact on consortium functioning. Our study presents the first proteome mapping of an antagonistic F. oxysporum strain and proposes candidate proteins that might play an important role for the biocontrol activity and the close interrelationship between the fungus and its bacterial partners.

Powdery Mildew Caused by Golovinomyces cichoracearum on Moth Mullein (Verbascum blattaria) in Italy

Moth mullein (Verbascum blattaria) is an herbaceous plant belonging to the Scrophulariaceae family. It has alternate, simple leaves on stiffly, erect, green stems. Flowers are yellow or white, borne in summer through fall, and is increasingly used in gardens in low-maintenance borders. During the fall of 2009, 4-month-old plants grown in a greenhouse near Torino (northern Italy) showed signs and symptoms of an unknown powdery mildew. The adaxial leaf surfaces were covered with white mycelia and conidia, while the abaxial surfaces were less infected. As the disease progressed, infected leaves turned yellow and wilted. Mycelia were also observed on stems, petioles, and flower calyxes of inflorescences. Powdery mildew was observed on moth mullein naturally diffused in Italian flora and on V. blattaria var albiflorum cv. White Blush. The same symptoms and signs were observed in summer 2010 on V. blattaria plants grown in a garden near Biella. Conidia were hyaline, elliptical, borne in short chains (as many as five conidia per chain), and measured 35 × 22 (29 to 42 × 19 to 24) μm. Conidiophores were erect with a cylindrical foot cell measuring 147 × 11 (93 to 177 × 10 to 12) μm, followed by one to two shorter cells measuring 23 × 11 (15 to 33 × 10 to 12) μm. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced (1) (GenBank Accession No. HQ316555). The 542-bp amplicon had 99% homology with the sequence of Golovinomyces cichoracearum (GenBank Accession No. EU819552. Pathogenicity was confirmed through inoculation by gently pressing diseased leaves onto leaves of healthy V. blattaria plants. Five plants were inoculated, while the same number of noninoculated plants served as a control. Plants were maintained at temperatures from 19 to 25°C. Fifteen days after inoculation, symptoms and signs of powdery mildew developed on inoculated plants. The conidial morphology of the powdery mildew fungus that developed on inoculated plants was identical to the conidial morphology observed in the original fungus. Noninoculated plants remained healthy. The pathogenicity test was carried out twice. G. cichoracearum, formerly Erysiphe verbasci (synonym E. cichoracearum), has been reported on V. blattaria in Hungary, Romania, and the former USSR (2,3). In conclusion, to our knowledge, it is the first report of G. cichoracearum affecting moth mullein in northern Italy. The economic importance of this disease is at present limited in Italy because of limited planting of this host. However, the ecological characteristics and flowering of V. blattaria make it interesting for low-maintenance gardens. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) K. Amano. Host Range and Geographical Distribution of the Powdery Mildew Fungi. Japan Scientific Societies Press. Tokyo, 1986. (3) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Stuttgart, Germany, 1995.

Effect of climate change on infection of grapevine by downy and powdery mildew under controlled environment

Plant responses to elevated CO2 and temperature have been much studied in recent years, but effects of climate change on pathological responses are largerly unknown. The pathosystems grapevine (Vitis vinifera) - downy mildew (Plasmopara viticola) and powdery mildew (Erysiphe necatrix) were chosen as models to assess the potential impact of increased CO2 and temperature on disease incidence and severity under controlled environment. Grapevine potted plants were grown in phytotrons under 4 different simulated climatic conditions: (1) standard temperature (ranging from 18 degrees to 22 degrees C) and standard CO2 concentration (450 ppm); (2) standard temperature and elevated CO2 concentration (800 ppm); (3) elevated temperature (ranging from 22 degrees to 26 degrees C, 4 degrees C higher than standard) and standard CO2 concentration; (4) elevated temperature and CO2 concentration. Each plant was inoculated with a spore suspension containing 5x10(5) cfu/ml. Disease index and physiological parameters (chlorophyll content, fluorescence, assimilation rate) were assessed. Results showed an increase of the chlorophyll content with higher temperatures and CO2 concentration, to which consequently corresponded an higher fluorescence index. Disease incidence of downy mildew increased when both CO2 and temperatures were higher, while an increase in CO2 did not influenced powdery mildew incidence, probably due to the increased photosynthetic activity of plants under such conditions. Considering that the rising concentrations of CO2 and other greenhouse gases will lead to an increase in global temperature and longer seasons, we can assume that this will allow more time for pathogens evolution and could increase pathogen survival, indirectly affecting downy and powdery mildews of grapevine.

Potential of two Metschnikowia pulcherrima (yeast) strains for in vitro biodegradation of patulin

Patulin contamination of apple and other fruit-based foods and beverages is an important food safety issue, as consumption of these commodities throughout the world is great. Studies are therefore necessary to reduce patulin levels to acceptable limits or undetectable levels to minimize toxicity. This study was undertaken to investigate the efficacy of two Metschnikowia pulcherrima strains (MACH1 and GS9) on biodegradation of patulin under in vitro conditions. These yeast strains were tested for their abilities to degrade patulin in liquid medium amended with 5, 7.5, 10, and 15 μg/ml patulin and a yeast cell concentration of 1 × 10(8) cells per ml at 25°C. Of the two strains tested, MACH1 completely (100%) reduced patulin levels within 48 h, and GS9 within 72 h, at all concentrations of patulin. MACH1 effectively degraded the patulin within 24 h by 83 to 87.4%, and GS9 by 73 to 75.6% at 48 h, regardless of concentration. Patulin was not detected in yeast cell walls. This indicates that yeast cell walls did not absorb patulin, and that they completely degraded the toxin. Patulin had no influence on yeast cell concentration during growth. Therefore, these yeast strains could potentially be used for the reduction of patulin in naturally contaminated fruit juices. To our knowledge, this is the first report regarding the potential of M. pulcherrima strains for patulin biodegradation.