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The genus Ceratocystis includes many important tree pathogens and agents of sap stain. These fungi have a global distribution and commonly infect wounds on trees. During a survey of woundinfecting pathogens in the genus Ceratocystis on plantation-grown Acacia mangium trees in Indonesia, several isolates resembling Ceratocystis moniliformis sensu lato (s.l.) were obtained. The aim of this study was to identify these isolates and to test their pathogenicity on commercially grown Acacia spp. in the country. Use was made of morphology and comparisons of DNA sequence data for the ITS, β-tubulin, and transcription elongation factor 1-α gene regions to identify the isolates. Three previously undescribed species in the C. moniliformis s.l. species complex were identified and are described here as C. inquinans sp. nov., C. sumatrana sp. nov., and C. microbasis sp. nov. Pathogenicity trials on Acacia mangium and A. crassicarpa in the greenhouse and in the field indicated that all three species have the potential to infect A. mangium and A. crassicarpa, although they are not considered important pathogens.

The recently described Cryphonectriaceae (Diaporthales) includes numerous important tree pathogens such as the chestnut blight pathogen Cryphonectria parasitica, and various species of Chrysoporthe that cause serious stem canker diseases on Eucalyptus. A recent investigation of dying Eucalyptus grandis clonal hedges in northern Sumatra, Indonesia, revealed the presence of an unknown member of the Cryphonectriaceae. DNA sequence comparisons with other members of the Cryphonectriaceae showed that the Indonesian fungus represents a new genus and species in the family, for which we provide the name Cryptometrion austuescens gen. sp. nov. It can be distinguished from other Cryphonectriaceae on Eucalyptus, such as Chrysoporthe, Microthia, Holocryphia and Cryphonectria, based on its orange, limited stromatic tissue, single septate, fusoid to ellipsoid ascospores and the absence of paraphyses among the conidiogenous cells in the anamorph. Inoculations with this fungus on two clones of E. grandis showed that it is highly pathogenic and has the capacity to cause serious losses to Eucalyptus plantations in the region.

Pruning (singling) is a common silvicultural practice in commercial Acacia plantations because these trees tend to have multiple stems. The wounds resulting from pruning are susceptible to infection by pathogens. Ceratocystis acaciivora and Lasiodiplodia theobromae have recently been shown to be important pathogens of A. mangium in Indonesia, where they are commonly associated with wounds on trees. The aim of this study was to determine the impact of different wound types on infection of A. mangium and A. crassicarpa by these two pathogens. Isolates of C. acaciivora and L. theobromae, found to be the most pathogenic in a prior study, were used to inoculate pruning wounds.Results showed that pruning conducted in a manner to reduce stem damage, resulted in lower levels of fungal infection. Where pruning resulted in tearing of the bark, there were greater levels of infection and disease occurred even without artificial inoculation.2 Inoculation of pruning wounds on A. mangium and A. crassicarpa showed that both fungi have the potential to cause disease. However, C. acaciivora was most pathogenic.Results of this study showed conclusively that careful pruning will result in lower levels of disease in young A. mangium and A. crassicarpa plantations in Indonesia.Keywords: Botryosphaeriaceae, Ceratocystis, disease management, silviculture, woundinfecting pathogens. IntroductionPlantations of Acacia mangium and A. crassicarpa have expanded rapidly in Indonesia since the 1980's, specifically to provide raw material for Indonesian pulp and paper industries (Barr 2001, Anonymous 2004. These Acacia spp., however, tend to have poor stem form, with multiple stems and branches (Srivastava 1993, Lee andArentz 1997).Pruning (singling) is thus carried out to improve tree form and to increase tree strength, reducing stem or branch breakage, particularly after strong winds (Beadle et al. 2007).Furthermore, the capacity of A. mangium trees to self prune is low in areas with high rainfall (Lee and Arentz 1997) and pruning is consequently necessary. These practices also reduce the density of stands so that optimum tree growth can be achieved (Neilsen and Gerrand 1999).Wounds resulting from pruning activities provide infection sites for numerous pathogens (Glass and McKenzie 1989, Vartiamaki et al. 2009), including plantation grown Acacia spp. (Lee et al. 1988, Barry et al. 2005. For example, heart rot caused by a complex of Phellinus noxius and other unidentified basidiomycetes is common on Acacia spp. in Malaysia and Indonesia (Lee and Sikin 1999). A recent study to 3 determine the cause of death of young A. mangium trees in Indonesian plantations (Tarigan 2008, Tarigan et al. 2010 has shown an association between pruning wounds and disease caused by Ceratocystis acaciivora and Lasiodiplodia theobromae.In order to develop management guidelines for pruning Acacia spp. in Indonesia, a study was undertaken to consider the effect of the quality of pruning wounds on disease development. For this purpose, pathogenic isolates of C. acaciivor...

Ceratocystis fimbriata sensu lato (s.l.) is an important pathogen of Eucalyptus. Pathogenicity of isolates has typically been evaluated by inoculating seedlings under greenhouse conditions. It is, however, not clear how accurately this reflects pathogenicity under field conditions. In this study, five techniques to potentially screen C. fimbriata isolates for their relative pathogenicity to Eucalyptus were compared. These included: in vitro growth comparisons on artificial media; inoculations on apples; inoculation on Eucalyptus seedlings in a greenhouse; inoculations on Eucalyptus bolts freshly cut from stems of young trees; and field inoculations on young trees. Eight isolates of C. fimbriata s.l. collected from various areas in South Africa were used. There was considerable variation in growth in culture and aggressiveness of the eight isolates. Field inoculations on young trees were best correlated with inoculations of bolts (r = 0.76). Lower correlation coefficients were obtained with seedlings (r = 0.59), apple inoculations (r = 0.56), and in vitro colony growth (r = 0.42). Inoculation of bolts provides a rapid and reliable method to screen isolates of C. fimbriata s.l. for pathogenicity to Eucalyptus.