First Report of Rhizopycnis vagum Associated with Tomato Roots in Italy.

Field surveys were made in several central and southern Italian tomato-growing areas for Pyrenochaeta lycopersici, the cause of corky root of tomato. In addition to P. lycopersici, a different fungus was frequently isolated from roots showing typical corky root symptoms, even after disinfestation of diseased roots with 0.1% (vol/wt) mercury chloride water solution for 1 min. The fungus was isolated from primary and secondary tomato roots in 8 of 21 fields visited. The isolates were grown on potato dextrose agar (PDA), with morphological features such as color and shape of mature conidia and pycnidia, type of conidiogenesis, presence of microsclerotia, and color of colony underside noted. Preliminary identification of the fungus was Rhizopycnis vagum Farr. To confirm the identification, the internal transcribed spacer (ITS) region of rDNA of one isolate (maintained at the ISPaVe collection at the authors' address and available on request as isolate ER 940) was amplified with two universal primers, ITS5 and ITS4. The ITS fragment was sequenced, and the nucleotide sequence compared with that of R. vagum deposited in GenBank (Accession No. AF022786). Both sequences were identical supporting the identification. R. vagum is a recently described species associated with the vine decline syndrome of melon in the United States, Guatemala, Honduras (2), and Spain (3). Eight isolates were tested for pathogenicity both on tomato (five cultivars) and melon (three cultivars) using two methods. In method 1, plantlets at the cotyledonary stage were grown on blotter in petri dishes and tested by placing a 6-mm plug of colonized PDA on the tap root (1). After 7 days, the plug was removed, and the roots were checked for symptoms. In method 2, 20-day-old seedlings were transferred to pots with infested soil (50,000 CFU/g of soil) and grown for 45 days before the roots were checked for each isolate-cultivar combination. Eight and four plants were used in tests 1 and 2, respectively. With the first method, rotten, pinkish lesions with different extensions from the inoculation point were observed on all the melon cultivars tested (Pamir, Cantalupo di Charentais, and Charme). On tomato, three of eight isolates caused root necrosis of limited extent, without pinkish discolorations at the inoculation site on cvs. Monalbo and Bonnie Best, the former showing the larger lesions. The tests on plants grown in infested soil confirmed pathogenicity on both host species, although the symptoms were of minor intensity (light, small brown lesions on secondary roots, no pinkish discoloration). The symptomatic plantlets ranged from 0 to 100% on both hosts in the petri dish tests and from 0 to 100% and 0 to 50%, respectively, for tomato and melon in the pot tests, varying according to the cultivar-isolate combination. The fungus was consistently reisolated from all symptomatic plants. To our knowledge, this is the first report of R. vagum associated with tomato roots. Although the isolates showed varying degrees of virulence with respect to host species (all being pathogenic at least on one host), the virulence of R. vagum on tomato was certainly low. Nevertheless, tomato may maintain or possibly increase inoculum for melon, which often follows tomato in Italian crop rotations. References: (1) M. Clerjeau and M. Conus. Annu. Rev. Phytopatol. 5:143, 1973. (2) D. F. Farr et al. Mycologia 90:290, 1998. (3) J. García-Jiménez et al. EPPO Bull. 30:169, 2000.

First Report of Sclerotium rolfsii on Sunflower in Italy.

During June 1996, 1-month-old sunflower plants (Helianthus annuus. L.) of the cvs. Blue Mix and Romsun × 590, grown at the experimental farm of the Istituto Sperimentale per la Nutrizione delle Piante (Montelibretti, Rome), showed symptoms of wilting, and then gradually dried out. Discolored areas were observed on the crown, where whitish, fan-shaped mycelia were occasionally present. A fungus was isolated on potato dextrose agar from surface-disinfested, diseased stem fragments. It also developed from diseased stem segments incubated in moist chambers. In both cases, round sclerotia developed after 9 days at room temperature. The fungus was identified as Sclerotium rolfsii Sacc. The fungus has been deposited in the ISPaVe collection (no. ER 883). To test pathogenicity, 20-day-old sunflower seedlings of the cvs. Blue Mix and Romsun × 590 were grown singly in an autoclaved peat/soil mixture in 20-cm-diameter plastic pots in a greenhouse at 30 ± 3°C. Plants were inoculated by placing five sclerotia of isolate ER 883 near the crown of each plant about 5 mm below the soil surface. For each cultivar, 10 plants were inoculated and 10 were left uninoculated. Wilting symptoms and stem discoloration appeared after 12 days. Sclerotia were produced at the stem base of some inoculated plants. All inoculated plants died after 20 days. S. rolfsii was consistently reisolated from all the inoculated plants, while no symptoms or signs were observed on the uninoculated plants. This is the first report of S. rolfsii on sunflower in Italy and has important implications for the use of sunflower in crop rotation. An unusual rainy period delayed planting of sunflowers by 1 month in 1996 and this could have favored the disease.

[Biomechanical changes in and lesions of the lumbosacral spine in horse riding. Magnetic resonance assessment]. / Modificazioni biomeccaniche e alterazioni traumatiche del rachide lombo-sacrale negli sport equestri. Valutazione con Risonanza Magnetica.

Spinal injuries account for 5-15% of sport-related traumas. Equestrian sports are considered, together with rugby, motor sport and diving, the riskiest sport for severe spinal injuries. We investigated the biomechanical changes and repeated microtraumas in equitation. We examined with MR the lumbar spines of 12 professional horsewomen and horsemen, 18-51 years old (mean: 33.4 years), belonging to F.I.S.E. (the Italian Federation for Equestrian Sports) and classified as Olympic riders, Senior and Young European riders. An 0.3-T resistive and an 0.2-T permanent magnets with dedicated surface coils were used. We also examined a control group of non-professional healthy volunteers homogeneous by age. MR findings were classified as follows: 1) changes in normal bending and angles of the lumbar spine; 2) injuries and changes in lumbar disks; 3) changes in spinal ligaments; 4) vertebral body injuries. MR was very sensitive in the assessment of all lumbosacral components in all the athletes; besides yielding useful findings to integrate with clinical results, MR also has a predictive value relative to both the continuation of sports activity and the possible damage at the end of it.