The Ganoderma weberianum-resinaceum lineage: multilocus phylogenetic analysis and morphology confirm G. mexicanum and G. parvulum in the Neotropics

Many species of Ganoderma exhibit a high phenotypic plasticity. Hence, particularly among them, the morphological species concept remains difficult to apply, resulting in a currently confused taxonomy; as a consequence, the geographical distribution range of many species also remains very uncertain. One of the areas with a strong uncertainty, as far as morphological species concept is concerned, is the Neotropics. It is common that names of species described from other regions, mainly from northern temperate areas, have been applied to Neotropical species. The aim of the present study was to determine which species might lay behind the G.weberianum complex in the Neotropics, using morphological studies and phylogenetic inferences based on both single (ITS) and multilocus (ITS, rpb2, and tef1-α) sequences. The results indicated that G.weberianumsensu Steyaert, which is the usually accepted concept for this taxon, was absent from the Neotropics. In this area, G.weberianumsensu Steyaert encompassed at least two phylogenetic species, which are tentatively, for the time being, identified as belonging to G.mexicanum and G.parvulum. These two species could be distinguished morphologically, notably by the ornamentation or its absence on their chlamydospores. The results also showed that additional species from the Neotropics might still exist, including, e.g., G.perzonatum, but their circumscription remains uncertain until now because of the paucity of material available. Furthermore, it was found that the current concept of G.resinaceum embraced a complex of species.

Fomitiporia rhamnoides sp. nov. (Hymenochaetales, Basidiomycota), a new polypore growing on Hippophae from China

Based on morphology and phylogenetic analysis, Fomitiporiarhamnoides sp. nov. is described. It is characterised by perennial, pileate basidiomata, distinctly shining poroid surface, a zonate context, 11–13 pores per mm, parallel tramal hyphae and regularly arranged contextual hyphae, the presence of cystidioles, globose, hyaline, thick-walled, smooth, dextrinoid, strongly cyanophilous basidiospores measuring 5.8–7 × 5.4–6.5 µm and growing on Hippophaerhamnoides in northern China. Fomitiporiarhamnoides differs from other Fomitiporia species growing on Hippophae by its smaller pores (11–13 per mm vs. <10 per mm).

Taxonomy and phylogenetic position of Fomitiporia torreyae, a causal agent of trunk rot on Sanbu-sugi, a cultivar of Japanese cedar (Cryptomeria japonica) in Japan

Trunk rot poses a substantial threat to Sanbu-sugi, one of the most economically important cultivars of Japanese cedar (Cryptomeria japonica). The etiology of this disease, including its main agents, is incompletely known. This trunk rot was attributed to Fomitiporia (Phellinus) hartigii or F. (Phellinus) punctata. Here we phylogenetically analyzed DNA sequences of four markers from a set of strains isolated from trunk-rot symptoms and recovered a single, monophyletic clade, indicating that a single taxon is involved. This clade was identified as Fomitiporia torreyae, a species described from eastern China. This analysis also proved that trunk rot and/or dieback of other conifers and broadleaf trees, including Sawara cypress (Chamaecyparis pisifera), Japanese umbrella pine (Sciadopitys verticillata) and Japanese pear (Pyrus pyrifolia var. culta), were caused by the same species. The phylogenetic approach to Fomitiporia revealed that the F. torreyae clade was closely related to F. bannaensis but clearly distinct from F. punctata, which originally was thought to be the cause of trunk rot in Sanbu-sugi. Fomitiporia torreyae is redescribed on the basis of more than 40 specimens from multiple hosts from Japan and China. Fomitiporia juniperina comb. nov. is proposed.

Emerging phytopathogen Macrophomina phaseolina: biology, economic importance and current diagnostic trends

Macrophomina phaseolina (Tassi) Goid. is an important phytopathogenic fungus, infecting a large number of plant species and surviving for up to 15 years in the soil as a saprophyte. Although considerable research related to the biology and ecology of Macrophomina has been conducted, it continues to cause huge economic losses in many crops. Research is needed to improve the identification and characterization of genetic variability within their epidemiological and pathological niches. Better understanding of the variability within the pathogen population for traits that influence fitness and soil survival will certainly lead to improved management strategies for Macrophomina. In this context, the present review discusses various biological aspects and distribution of M. phaseolina throughout the world and their importance to different plant species. Accurate identification of the fungus has been aided with the use of nucleic acid-based molecular techniques. The development of PCR-based methods for identification and detection of M. phaseolina are highly sensitive and specific. Early diagnosis and accurate detection of pathogens is an essential step in plant disease management as well as quarantine. The progress in the development of various molecular tools used for the detection, identification and characterization of Macrophomina isolates were also discussed.