Biocontrol of Rust Fungi by Cladosporium tenuissimum

This chapter examines whether Cladosporium tenuissimum Cooke, a destructive hyperparasite of rust spores, can be exploited as a BCA of rust fungi. It reports on tests carried out to evaluate C. tenuissimum effectiveness against rusts in the genera Melampsora, Cronartium, Peridermium, Uromyces and Puccinia, focusing on its modes of action, the fine-level analysis of the fungal host\u2013hyperparasite interface, the antifungal compounds it produces, and its ability to reduce disease, both in vitro and in planta. Since effective biological control is impossible without due consideration of the ecology of the BCA, as well as of the other partners involved, and an examination of their spatial relationships and interaction with the environment, attention is also paid to the biological nature of the fungus, in particular to those characteristics that enable it to survive in natural habitats and retain activity under varying environmental conditions

Status of charcoal canker on oak trees at a site of community importance: case study of the relict castelfidardo forest (Sic area it520008, castelfidardo, an, Italy)

Oaks are dominant and key tree species in Mediterranean forest ecosystems. However, in recent decades, oak forests have been heavily impacted by oak decline, a worldwide phenomenon exacerbated by climate change. The charcoal disease agent Biscogniauxia mediterranea is involved in the decline of Mediterranean oak formations in a variety of contexts. Here, we investigated the impact and role of B. mediterranea in the decline of oaks in Castelfidardo Forest, a relict wood of the late Holocene and a Site of Community Importance. We established five plots within which we recorded tree positions, any symptoms and signs of decline, association of B. mediterranea to declining trees, and deadwood and associated mycota. Of 471 oaks inspected, 7.0% showed brownish exudates on the stems, 46.9% showed epicormic shoots along the main trunk, and 24.4% showed black carbonaceous stromata on diseased branches and trunks. The decline was most severe for Quercus cerris, which comprised plots #4 and #5, at 50.0% (81/162 trees) and 29.0% (33/114), respectively; then for Quercus robur for plot #3, at 40.0% (38/95); and finally for Quercus pubescens for plots #1 and #2, at 13.7% (7/51) and 12.3% (6/49), respectively. Bark tissues were collected from trees with charcoal cankers and taken to the laboratory for microscopic examination and identification by mycological and molecular methods. This investigation revealed a close association between oaks with pronounced reduction of vitality and incidence of B. mediterranea. Deadwood was equally distributed among the five plots, and was heavily colonized by Basidiomycota. The high incidence of the charcoal canker pathogen B. mediterranea appeared to be related to environmental stresses. However, the absence of silvicultural management, high competition among physiologically mature trees, and the geographic isolation of this residual forest may have predisposed oaks to decline

Hyperthermic Perfusion 16 Years After its First Clinical Applications

It is known that above-normal temperatures (42°-42.5°C) provoke selective damage to neoplastic cells. We used heated circulating blood as a method for heat transfer on patients with limb tumors. From October 1964 to December 1979, we treated a total of 198 patients with hyperthermic perfusion for melanoma of the limbs (91), osteosarcoma (57), and soft tissue sarcoma (50). For melanoma patients, the five-year survival rate, excluding Stage IV, was 60%. For patients with soft tissue sarcoma, the five-year survival rates were 53% and 56% for hyperthermic perfusion and hyperthermic antiblastic perfusion. respectively. For 29 patients with osteosarcoma, hyperthermic perfusion was combined with systematic amputation ofthe limb for a 60% survival rate over a five-year period. Newer studies with osteosarcoma patients involve a multistep treatment that saves the tumor-bearing limb without reducing survival rates. Our 16-year clinical trial demonstrates that hyperthermia is effective in curing some tumors of the limbs, especially osteosarcoma and melanoma. We believe that perfusion remains the most reliable heat transfer method for loco-regional treatment and perhaps even for whole-body treatment for limb tumors

Phytophthora root and collar rot of Paulownia, a new disease for Europe

Paulownia species are fast growing trees native to China, which are being grown in managed plantings in several European countries for the production of wood and biomasses. In 2018, wilting, stunting, leaf yellowing, and collapse, as a consequence of root and crown rot, were observed in around 40% of trees of a 2-year-old planting of Paulownia elongata × P. fortunei in Calabria (Southern Italy). Two species of Phytophthora were consistently recovered from roots, basal stem bark, and rhizosphere soil of symptomatic trees and were identified as Ph. nicotianae and Ph. palmivora on the basis of both morphological characteristics and phylogenetic analysis of rDNA ITS sequences. Koch’s postulates were fulfilled by reproducing the symptoms on potted paulownia saplings transplanted into infested soil or stem-inoculated by wounding. Both Phytophthora species were pathogenic and caused root rot and stem cankers. Even though P. palmivora was the only species recovered from roots of naturally infected plants, in pathogenicity tests through infested soil P. nicotianae was more virulent. This is the first report of Phytophthora root and crown rot of a Paulownia species in Europe. Strategies to prevent this emerging disease include the use of healthy nursery plants, choice of well-drained soils for new plantations, and proper irrigation management

Disease gradient of the anthracnose agent Apiognomonia quercina in a natural oak stand

Patterns of spore dispersal of the fungal pathogen Apiognomonia quercina and its anamorph Discula quercina were investigated over two consecutive growing seasons in a natural mixed stand of Quercus cerris and Q. pubescens trees located in a inland area of Tuscany, at an altitude of 400 m a.s.l. To measure spore dispersal, a transect was laid out in the stand to serve as an inoculum source. The rate of inoculum dispersal (conidia and ascospores) was quantifi ed by means of spore traps positioned at 10, 100, 500 and 1000 m from the southern end of the transect. The disease gradient was also assessed by determining the disease incidence on selected trees at the same distances from the transect. The amount of inoculum detected decreased steeply with the distance from the transect. Disease incidence was inversely correlated with the disease gradient, i.e. with the distance from the inoculum source, and it was much higher at the shorter distances. The level of spore dispersal was related to both the distance from the infection foci and the sporulation time. The experimental approach constituted a valid means for describing and understanding the dynamics of windborne diseases in forests