Chrysoporthe brasiliensis sp. nov. pathogenic to Melastomataceae in southeast Brazil.

Species in the Melastomataceae (Myrtales) include trees and woody shrubs that are amongst the most common hosts of Chrysoporthe and related fungi. These fungi cause stem cankers, branch death and in extreme cases, kill their hosts. Chrysoporthe-like fungi were observed on Miconia spp. and Rhynchanthera grandiflora (Melastomataceae) plants during tree disease surveys in south-eastern Brazil including the states of Minas Gerais and Rio de Janeiro. The aims of this study were to isolate and identify the fungi utilising morphological characteristics and phylogenetic analyses. This led to the identification of a new species of Chrysoporthe described here as Chrysoporthe brasilensis sp.nov. Inoculations were conducted on R. grandiflora and M. theaezans, showing that C. brasiliensis is an aggressive pathogen. This study adds to a growing number of reports of new and pathogenic species of Chrysoporthe that potentially threaten native Myrtales globally, including important trees such as Eucalyptus, both in natural ecosystems and in planted forests.

Two new species of Calonectria (Hypocreales, Nectriaceae) causing Eucalyptus leaf blight in Brazil.

In recent decades, commercial Eucalyptus plantations have expanded toward the warm and humid regions of northern and northeastern Brazil, where Calonectria leaf blight (CLB) has become the primary fungal leaf disease of this crop. CLB can be caused by different Calonectria species, and previous studies have indicated that Calonectria might have high species diversity in Brazil. During a disease survey conducted in three commercial plantations of Eucalyptus in northeastern Brazil, diseased leaves from Eucalyptus trees with typical symptoms of CLB were collected, and Calonectria fungi were isolated. Based on phylogenetic analyses of six gene regions (act, cmdA, his3, rpb2, tef1, and tub2) and morphological characteristics, two new species of Calonectria were identified. Five isolates were named as C.paragominensis sp. nov. and four were named as C.imperata sp. nov. The pathogenicity to Eucalyptus of both species was confirmed by fulfilling the Koch's postulates.

IMA genome - F14 : Draft genome sequences of Penicillium roqueforti, Fusarium sororula, Chrysoporthe puriensis, and Chalaropsis populi.

Draft genomes of Penicillium roqueforti, Fusarium sororula, Chalaropsis populi, and Chrysoporthe puriensis are presented. Penicillium roqueforti is a model fungus for genetics, physiological and metabolic studies, as well as for biotechnological applications. Fusarium sororula and Chrysoporthe puriensis are important tree pathogens, and Chalaropsis populi is a soil-borne root-pathogen. The genome sequences presented here thus contribute towards a better understanding of both the pathogenicity and biotechnological potential of these species.

Wood-associated fungi produce volatile organic compounds toxic to root-knot nematode

Since volatiles do not leave residues in food and cause low toxicity to humans, they can act as a skeleton for new nematicidal molecules, once they have demonstrated activity against phytonematodes. The aim of this study was to evaluate the effect of volatile organic compounds (VOCs) released by wood-associated fungi on controling second-stage juveniles (J2) of Meloidogyne incognita. All 28 wood-associated fungi isolates produced VOCs which caused in excess of 76 % immobility in exposed J2 of M. incognita. The fungus isolate VOCs also caused significant mortality compared to control when J2 were exposed to them. After 6 h of exposure, the fungus species Epicoccum nigrum and Schizophyllum commune produced VOCs that immobilized exposed J2 compounds, in relation to the control. When J2 were inoculated into tomato under greenhouse conditions, the M. incognita infectivity and reproduction were reduced by exposure to the VOCs. Volatiles produced by most of the fungi isolates and analyzed by gas chromatograph coupled to a mass spectrometer (CG-MS), included alcohols, esters, terpenes, and ketones. Certain compounds appeared only in S. commune or in E. nigrum suggesting their involvement in the high level of damage caused to nematode reproduction on tomato. Volatiles emitted by wood fungi demonstrated another mode of action of these microorganisms in nature.

Wood-associated fungi produce volatile organic compounds toxic to root-knot nematode

Since volatiles do not leave residues in food and cause low toxicity to humans, they can act as a skeleton for new nematicidal molecules, once they have demonstrated activity against phytonematodes. The aim of this study was to evaluate the effect of volatile organic compounds (VOCs) released by wood-associated fungi on controling second-stage juveniles (J2) of Meloidogyne incognita. All 28 wood-associated fungi isolates produced VOCs which caused in excess of 76 % immobility in exposed J2 of M. incognita. The fungus isolate VOCs also caused significant mortality compared to control when J2 were exposed to them. After 6 h of exposure, the fungus species Epicoccum nigrum and Schizophyllum commune produced VOCs that immobilized exposed J2 compounds, in relation to the control. When J2 were inoculated into tomato under greenhouse conditions, the M. incognita infectivity and reproduction were reduced by exposure to the VOCs. Volatiles produced by most of the fungi isolates and analyzed by gas chromatograph coupled to a mass spectrometer (CG-MS), included alcohols, esters, terpenes, and ketones. Certain compounds appeared only in S. commune or in E. nigrum suggesting their involvement in the high level of damage caused to nematode reproduction on tomato. Volatiles emitted by wood fungi demonstrated another mode of action of these microorganisms in nature.(AU)