Occurrence of Phaeomoniella chlamydospora on grapevine planting material in Sardinia and its control with combined hot water and cyproconazole treatment.

The occurrence of Phaeomoniella chlamydospora was investigated during the propagation process of an Italian nursery, and combined hot water and cyproconazole treatments were carried out to limit its spread in nursery plants. In the three–year period 2005–07, cutting and graft samples (scion cv Sangiovese, rootstock cvs 140Ru in 2005 and 1103P in 2006–07) were taken during the propagation process at several infection risk stages in order to assess the presence of P. chlamydospora. Moreover, in 2005 and 2006 cuttings from esca–symptomatic grapevines (scion cv Sauvignon blanc, rootstock cvs 140Ru in 2005 and 1103P in 2006) were treated at different stages of the propagation process. In 2007, artificially infected 1103P cuttings were treated after inoculation with P. chlamydospora (107 conidia ml-1). Cuttings and callused graftlings were treated by dipping in a hot water bath at 50°C for 30 min (HWT) or in a cyproconazole suspension (0,1 g a.i. l-1) for at least 12 h, in different combinations. At each stage of infection risk and at each treatment woody material was collected and grown in pot, avoiding accidental contamination, or in the field nursery for one season and then destructively examined. DNA was extracted from wood collected at different points along the plant and analysed by nested PCR with Pch-specific primers. One-mm thick woody slices from artificially inoculated cuttings were plated on MEA plus antibiotics and fungicides. Despite the extended wood discoloration, P. chlamydospora occurrence on nursery plants was scarce in the three–year period. Planting material contamination may have resulted from infected mother plants (from 0.0 to 6.7 % of infected cuttings were obtained directly from non-symptomatic mother plants) or from the propagation process, particularly during the stages following grafting (0.0 to 23.3 % of infected grafts). Canes from esca–diseased mother plants were always contaminated, but in quite different percentages (about 30 % of the cuttings examined in 2005, from 1.9 to 4.1 % in 2006 and 2007). However, no final conclusion could be drawn about which stages played a major role in the contamination of nursery plants, due to the low and irregular infection frequencies detected in the propagation process. As regards P. chlamydospora control, HWT performed on cuttings before or after cold storage influenced vegetative growth depending on both the cultivar and the growth conditions, but it was deleterious on callused graftlings. Natural contamination on nursery material in 2005 and 2006 was insufficient to assess the effectiveness of treatments. In 2007, HWT and cyproconzole treatments alone were not effective in reducing the percentage of infection in cuttings that were artificially inoculated. Only cyproconazole immediately followed by HWT significantly reduced the number of infected cuttings, but it was not sufficient to eradicate the pathogen

Studies on the susceptibility of pruning wounds to infection by fungi involved in grapevine wood diseases in Italy

The susceptibility of grapevine annual pruning wounds to Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and Diplodia seriata was investigated over three years (2005–2007) in a 15 year-old vineyard, cv. Sauvignon blanc. Vines were pruned each year in January, February and March and the wounds were inoculated weekly with conidial suspensions, and with sterile water as a control. Penetration of the fungi into the wood was assessed after 4 weeks by plating pieces of host tissue on agar medium. The susceptibility of annual pruning wounds, expressed as the infection percentages of inoculated spurs, varied with both the trial year and the fungus inoculated. Average infection percentages of inoculated spurs in the three years were respectively 14.7, 38.5 and 50.9% for Pa. chlamydospora, 31.7, 32.2 and 49.4% for Pm. aleophilum and 84.2, 43.8 and 40.9% for D. seriata. The period of pruning was significant for the infection percentages of all fungi in 2005, and for D. seriata in 2006. Natural infection of control spurs by Pa. chlamydospora (2, 4.4, and 11.7% of spurs in the three years respectively) and by Pm. aleophilum (0.3, 1.8, and 6.4%) began when average weekly temperatures stabilized around 10°C, while infection by D. seriata (12.2, 12 and 18.3% in the same period) occurred even below that threshold. Higher infection percentages of both artificially and naturally infected spurs in 2007 were probably due to the higher temperatures recorded in February and March (besides the use of a more efficient selective medium for the isolation of Pa. chlamydospora and Pm. aleophilum). Only artificial infections with D. seriata showed an opposite trend that cannot be explained by the weather data. Infection of one-year-old wood appeared to be an important factor in disease spread. Spurs remained liable to infections with any of the fungi for up to 4 months after pruning, and isolation percentages could be fairly high also in late spring. As a consequence, the planning of pruning does not seem to be an effective means to counteract the wood diseases caused by these fungi

Occurrence, isolation and biological activity of phytotoxic metabolites produced <i>in vitro</i> by <i>Sphaeropsis sapinea</i>, pathogenic fungus of <i>Pinus radiata</i>

Sphaeropsis sapinea was repeatedly isolated in Sardinia from symptomatic samples of the upper part of declining pine (Pinus radiata) plants. Observed symptoms mainly consisted of foliage chlorosis, drying of needles and cankers on branches. The S. sapinea strains were shown to produce phytotoxic metabolites in culture filtrates. Three metabolites were isolated for the first time from this fungus and identified by their spectroscopic and optical properties as R-())-mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein. When assayed for phytotoxic and antifungal activities on host and non-host plants and on some phytopathogenic fungi, the R-())-mellein showed significant activity, while the other two 3,4-dihydroisocoumarins showed only a synergic activity in both tests

Observations on the history and uses of animation occasioned by the exhibition Eyes Lies and Illusions selected from works in the Werner Nekes collection

The 500 items selected from Werner Nekes' collection of 20,000 (accompanied by a judicious selection of recent works) in the exhibition Eyes Lies and Illusions (at the Australian Centre for the Moving Image, Thursday 2 November 2006 - Sunday 11 February 2007; previously shown at the Hayward Gallery, London in the winter of 2004-5) sketch a 400-year history of optical tools, toys and tricks. To consider them as 'pre-cinema' is to do them an injustice, pre-empting their intrinsic fascination by delivering them over to a technology their makers could scarcely have imagined.Their abiding fascination is as much about the possibility of playing with them in the present as with a Benjaminian dislocation of the recent past. It belongs, so, to a shared history of technique, and a common concern with what constitutes us as human, rather than to a catalogue of failed attempts to produce La Sortie des usines Lumières