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Phellinus noxius, the cause of brown root-rot disease, is an invasive fungal pathogen that causes a white rot among woody plants in Asia, Oceania, and Africa. Because the origin and diversity of this pathogen are unknown, it is difficult to predict its behavior and invasive capacity, especially under future climate-change scenarios. We characterized genetic relationships and ecological differences among P. noxius lineages across eastern Asia and Oceania to better understand evolutionary responses of the pathogen to environmental changes. Sequences of four loci (nuclear large subunit, internal transcribed spacers, partial RNA polymerase II, and partial translation elongation factor – 1 alpha) from 95 P. noxius isolates were used for genetic analyses. Our analyses revealed three genetically distinct lineages of P. noxius: 1) eastern Asia (Japan, Taiwan, Hong Kong, and Malaysia); 2) western Oceania/Japan/Taiwan (including Australia, Palau, Guam, Saipan, Yap, Pohnpei, and Kosrae) with some isolates from Japan and Taiwan; and 3) a distinct group from American Samoa. Population genetic analyses highlighted admixture and migration among the three lineages. Climate-based, species distribution models were used to predict ecological patterns of P. noxius for two genetic lineages: eastern Asia and western Oceania/Japan/Taiwan. Contemporary bioclimatic models depicted potential areas at high risk for P. noxius invasion, and predicted that suitable climate space (potential distribution) is lineage specific. Trade of important economic crops worldwide coupled with changing climates could exacerbate the spread of P. noxius into new geographic areas with suitable habitats for brown root-rot disease.

We present a taxonomic study of ‘group Favolus’ and related species in Polyporus. Phylogenetic analyses of nurLSU and ITS regions revealed that the infrageneric ‘group Favolus’ is divided into two main clades. Fungi within the group share laterally stipitate basidiocarps, with non-crustose stipe surfaces, and are distinguishable by the morphology of the pileus surface. One clade is characterized by species with hyaline to brown cutis, composed of hyaline to brown agglutinated generative hyphae. The other clade accommodates species with radially striate pileus, and lacks any distinct cutis of agglutinated hyphae. We propose Neofavolus gen. nov., typified by N. alveolaris, for the former clade, and revise the genus Favolus, typified by F. brasiliensis, for the latter clade. Neofavolus includes N. mikawai and N. cremeoalbidus sp. nov., known only from temperate eastern Asia, in addition to N. alveolaris. Favolus includes members of the Polyporus grammocephalus complex, the P. tenuiculus complex, and P. pseudobetulinus. We reveal that the polypore known as ‘P. grammocephalus’ in Asia includes F. acervatus and F. emerici (= P. grammocephalus), whereas ‘P. tenuiculus’ includes three distinct species; F. brasiliensis from tropical America, and F. spathulatus and F. roseus from tropical Asia. Detailed descriptions and illustrations are provided for the accepted species in Favolus and Neofavolus.

We reviewed the ecological characteristics of wood-inhabiting fungi in Malaysia in relation to the major threats to these fungi; we also examined the forest uses that would help to conserve them. Although wood-inhabiting fungi do not show high host specificity or preference in many tropical areas, several are specific to Dipterocarpaceae trees in Malaysia and some species may preferably inhabit other minor tree species. Tree size and decomposition stage are also important determinants of which fungi are present. Among the polypores described by E. J. H. Corner, 41 and 26 species have been recorded only from Malaysian lowland rainforest and montane forest, respectively. Evidence suggests that both of these forest types in Malaysia are home to unique fungal communities. More than 30 polypore species described by Corner are known only from their type localities. These species are likely rare and may be restricted to old-growth forests. Logging decreases species richness of wood-inhabiting fungi because the number of natural treefalls is decreased in logged forests, and the decline of old-growth forests is a major threat to conservation of Malaysian fungi. However, species richness of wood-inhabiting fungi is relatively high in old secondary forests and forests undergoing reduced-impact logging. The diversity of wood-inhabiting fungi is extremely low in oil palm plantations, whereas several species inhabit rubber-tree and acacia plantations. Preservation of old-growth forest is essential for conserving rare wood-inhabiting fungi in Malaysia, but old secondary forests, reduced-impact logged forests, and matured tree plantations may have some importance for the conservation of some species.

The genus Amanita is well represented in tropical Africa, but most previous taxonomic studies were largely based only on morphology. In this study, we used both morphological and molecular data (nLSU sequences) to infer the phylogenetic relationships of ten species of Amanita sect. Vaginatae s.l. from tropical Africa. It was found that all five species with both an annulus and commonly present clamp connections in the basidioma were clustered in the sect. Caesareae. One species with neither an annulus nor clamp connections was placed in sect. Vaginatae s.s. The remaining four taxa with an annulus, but without clamp connections were interestingly also grouped into sect. Vaginatae s.s. with strong statistical support. Consequently, the section Vaginatae s.s. should be slightly modified to include tropical species with an annulus. As a new species, A. madagascariensis was described and illustrated. Amanita tanzanica was treated as a synonym of A. mafingensis.

A taxonomic study of poroid Asian species in the Auriculariales was conducted using phylogenetic and morphological methods. Phylogenetic analyses based on the LSU and ITS regions reveal that Elmerina was a polyphyletic genus. Moreover, E. hexagonoides collected from Malaysia and “E. hexagonoides” from Japan formed two distinct clades within a well-supported larger clade with Protomerulius caryae. These taxa comprise a different lineage from the type species of both Protomerulius and Protodaedalea, and we conclude that they are members of the genus Aporpium. The phylogenetic position of E. cladophora (type species of Elmerina) is still unclear, and we retain Aporpium and Protodaedalea as genera distinct from Elmerina. Aporpium strigosum sp. nov. is described to represent Japanese specimens misidentified as E. hexagonoides. Aporpium is characterized by resupinate to sessile basidiocarps, tough-fleshy to leathery context, poroid hymenophore, dimitic hyphal systems with unbranched skeletal hyphae, clavate to pyriform probasidia, and ellipsoid to cylindrical or allantoid basidiospores. Aporpium strigosum is similar to A. hexagonoides, but can be differentiated by the ochraceous to straw-colored basidiocarps, strigose pileus surface with long and stiff hairs, and the larger pores, basidia, and basidiospores.

Fungal sporocarps and cultures associated with signs and symptoms of root-rot disease were collected from Acacia mangium and other tropical hardwood species. The collections were identified by either morphological characters and/or by phylogenetic analysis based on DNA sequences as Ganoderma philippii, G. mastoporum, G. aff. steyaertanum, G. australe and Amauroderma rugosum. Phylogenetic analysis unequivocally placed in the G. philippii clade four sequences amplified from A. mangium root and butt tissue showing clear signs of red root-rot disease (roots are covered by a red rhizomorphic skin). Whereas G. philippii was the most frequently encountered fungal species in A. mangium with red root-rot disease, this study indicates that other fungal species related to G. mastoporum may cause root-rot disease with very similar symptoms. An isolate (FRIM 138) that had caused red root-rot disease in artificial inoculations carried out before this study and was presumed to be G. philippii, is here determined to be closely related to G. mastoporum, G. cupreum and G. sinense. A Ganoderma species associated with a yellow-brown root-rot disease killing trees in an A. mangium plantation in Central Java, previously identified as G. lucidum, is shown by phylogenetic analysis to be closely related to G. steyaertanum, though some morphological characters vary from the original description of that species.

Wood decay associated with wounding in 40 trees of Parashorea malaanonan growing in Ulu Segama Forest Reserve, Sabah, Malaysia, was estimated 7 years after logging in compartments where reduced-impact (RIL) or conventional (CL) logging methods were used. Trees of ≥30 cm diameter were felled and dissected to determine the volume of log occupied by decay. Scrapes were the most common types of wounds sampled, followed by basal wounds, broken tops or branches and butt log wounds. All wounded trees examined had decay, whereas only 25% of trees ×30 cm diameter at breast height of this species in the reserve typically had stem decay. Median defect to gross volume of tree was ∼5%, and was similar for trees in RIL and CL areas. However, defect volume per wound was greater in trees from CL areas relative to RIL areas, in particular, mid-bole wounds had greater defect volume in trees in CL areas as opposed to trees in RIL areas. The mean rate of decay was estimated at 68 cm3 of timber per year for each cm2 of wound area. Defect volume was positively correlated with wound size but was unrelated to tree size. P. malaanonan is vulnerable to wood decay following wounding; therefore, in eastern Sabah forests, where this species comprises a large proportion of the commercial volume, efforts to reduce incidental damage to residual stems during harvesting operations are an important component in protecting the growing stock.

This is the first report of basal root rot of teak, caused by Phellinus noxius, in Peninsular Malaysia. The disease aggressively killed its host irrespective of health status. Bark depression at the root collar was a very characteristic symptom of this disease on teak and was visible from a distance. Below ground, infected trees had rotted root systems, mainly at the collar region, brown discoloured wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the roots. Pathogenicity tests showed that the fungus killed 2-year-old teak saplings gradually, producing below- and above ground-symptoms similar to those in the plantation. The disease killed all the infected hosts within 3 months, irrespective of wounded or unwounded treatments. Additional keywords: forest plantation, root disease, teak, Tectona grandis.