The genus <Emphasis Type="Italic">Diaporthe</Emphasis>: a rich source of diverse and bioactive metabolites

The genus Diaporthe (asexual state: Phomopsis) comprises pathogenic, endophytic and saprobic species with both temperate and tropical distributions. Although species of Diaporthe have in the past chiefly been distinguished based on host association, studies have confirmed several taxa to have wide host ranges, suggesting that they move freely between hosts, frequently co-colonizing diseased or dead tissue, while some species are known to be host-specific. They are also very frequently isolated as endophytes of seed plants. Due to their importance as plant pathogens, the genus has been thoroughly investigated for secondary metabolites, including during screening programs aimed at the discovery of novel bioactive natural products, but the respective information has never been compiled. Therefore, we have examined the relevant literature to explore and highlight the major classes of metabolites of Diaporthe and their Phomopsis conidial states. These fungi predominantly produce a large number of polyketides, but cytochalasins and other types of commonly encountered fungal secondary metabolites are also predominant in some species. Interestingly, not a single metabolite which is also known from the host plant has ever been isolated as a major component from an endophytic Diaporthe strain, despite the fact that many of the recent studies were targeting endophytic fungi of medicinal plants.     

<Emphasis Type="Italic">Basidiophora delawarensis</Emphasis>, a new downy mildew species infecting cultivated goldenrod (<Emphasis Type="Italic">Solidago sphacelata</Emphasis>) in the USA

Species in the genus Basidiophora (Oomycota, Peronosporales) are pathogens causing downy mildew disease on several closely related plant hosts in the family Asteraceae, including the genera Conyza, Erigeron, Solidago, and Symphyotrichum. Despite their widespread occurrence, little is known about the diversity, biology, and economic impact of downy mildew pathogens of ornamental or wild plants in the Asteraceae. In June 2017, Solidago sphacelata plants of the cultivar ‘Golden Fleece’ were found in the state of Delaware, USA, showing typical symptoms of downy mildew disease. Initial morphological observations indicated the specimen belonged to the genus Basidiophora. Phylogenetic analysis of a sequence matrix of the partial cox2 mitochondrial gene using Bayesian and maximum likelihood methods showed that the Basidiophora isolate from S. sphacelata represents an undescribed species that is here described as B. delawarensis. This new species constitutes the third accepted species in the genus Basidiophora and can be distinguished from other Basidiophora species by differences in size of sporangia and sporangiophores and nucleotide sequence divergence. This new species poses a potential threat to its host, warranting close monitoring and the implementation of disease management programs.     

Two new quill mite species of the genus <Emphasis Type="Italic">Psittaciphilus</Emphasis> Fain,Bochkov &amp; Mironov, 2000 (Acariformes: Syringophilidae) associated with pigeons and doves (Columbiformes: Columbidae)

Two new quill mite species of the genus Psittaciphilus Fain, Bochkov & Mironov, 2000 (Acariformes: Prostigmata: Syringophilidae) collected from columbiform birds (Columbiformes) are described: Psittaciphilus montanus n. sp. form the ruddy quail-dove Geotrygon montana Gosse from Trinidad and Tobago, Brazil and Panama, and Psittaciphilus patagioenas n. sp. from the band-tailed pigeon Patagioenas fasciata (Say) from Colombia and the scaled pigeon Patagioenas speciosa (Gmelin) from Surinam. A key to the species of the genus Psittaciphilus is provided. Our finding is the first record of the representatives of this genus on columbiform birds.     

Relationships between the gall-midge genera <Emphasis Type="Italic">Trotteria</Emphasis> and <Emphasis Type="Italic">Verbasciola</Emphasis> (Diptera,Cecidomyiidae), with description of new species from the Middle Volga River Area

Gall midges of the genera Trotteria and Verbasciola of the supertribe Lasiopteridi are inquilines. The widespread genus Trotteria includes 28 species developing in galls of 30 species of gall midges; 24 species develop in galls of Asphondyliidi. Gall midges-hosts and inquilines were found on 57 plant species of 17 families. The Palaearctic genus Verbasciola comprises three species that have been recorded in galls of three gall-midge species damaging three plant species. Seven new species are described, Trotteria coronillacola, T. perkovskii, T. cytisiphila, T. kalininae, T. jigulensis, Schizomyia samaralukensis, and Verbasciola volgensis. The diagnoses of the genera were corrected. Trotteria spinosa Kovalev is restored from the synonyms of T. umbelliferarum Kieffer. Data on the distribution of all the species examined and their associations with host gall midges and taxonomic groups of plants are given.     

A synopsis of gall midges associated with conifers,with description of a new species of the genus <Emphasis Type="Italic">Kaltenbachiola</Emphasis> Hedicke (Diptera,Cecidomyiidae: Lasiopterinae) from Yakutia,damaging cones of the Siberian spruce (<Emphasis Type="Italic">Picea obovata</Emphasis>)

The world fauna comprises 134 species from 52 genera of gall midges associated with plants of the order Pinales (3 families, 16 genera and 74 species); 14 genera are specific to Pinales. The distribution of genera and species of gall midges over host plant taxa is described. The Holarctic genus Kaltenbachiola comprises four species all developing in the spruce (Picea spp.) cones. Earlier, K. strobi (Winnertz), widely distributed in Europe, was the only species known in the Palaearctic. A new species Kaltenbachiola anastasiae sp. n. is described, which damages cones of Picea obovata in Central Yakutia. The phylogenetic relationships of Kaltenbachiola with close genera specific to Pinales are characterized, and an updated diagnosis of the genus with additional morphometric parameters and keys to the pine-specific genera of the tribe Dasineurini and to species of the genus Kaltenbachiola are given. The host associations and specific traits of biology and distribution of Kaltenbachiola species are considered.     

Molecular phylogeny,morphology and pathogenicity of <Emphasis Type="Italic">Pseudopestalotiopsis</Emphasis> species on <Emphasis Type="Italic">Ixora</Emphasis> in Taiwan

Pestalotiopsis-like species are phytopathogenic, causing numerous diseases on different hosts, and are widely distributed in tropical and temperate ecosystems. These taxa were recently segregated into several genera and species having brown to dark brown or olivaceous median cells, with or without knobbed apical appendages, were classified under the new genus Pseudopestalotiopsis. Pseudopestalotiopsis species are well known for their capability to produce novel medicinal compounds that may have medicinal, agricultural and industrial applications. Ixora is among the largest genera in the family Rubiaceae and is cultivated throughout Taiwan, as a garden plant. During a survey of fungal diseases associated with Ixora species in Taiwan, several Pestalotiopsis-like species causing leaf spot were isolated. Based on morphology coupled with single- and multi-gene (ITS, TUB, TEF) phylogenies, these taxa belong to two novel species of Pseudopestalotiopsis and are introduced herein as Ps. ixorae and Ps. taiwanensis. These two new taxa fit well with Pseudopestalotiopsis in having dark concolourous median cells with knobbed apical appendages, but differ from the known species in the size of conidiomata, size of the conidia, the number of apical appendages, the length of basal appendages plus ecology and distribution. Pathogenicity testing showed that Ps. ixorae and Ps. taiwanensis are capable of causing leaf disease on Ixora and to the best of our knowledge, this is the first record of Pseudopestalotiopsis species associated with leaf spots of Ixora in Taiwan.     

A new species <Emphasis Type="Italic">Selenonycha insperata</Emphasis> n. sp. (Acariformes: Syringophilidae) from the bare-faced ibis <Emphasis Type="Italic">Phimosus infuscatus</Emphasis> (Lichtenstein) (Pelecaniformes: Threskiornithidae) as an example of host-switching event

A new quill mite species of the family Syringophilidae (Acariformes: Prostigmata: Cheyletoidea) is described from Phimosus infuscatus (Lichtenstein) (Pelecaniformes: Threskiornithidae) in Argentina. Selenonycha insperata n. sp. differs from other species of the genus Selenonycha Kethley, 1970 by the presence of wing-like cuticular projections of coxal fields III–IV situated in front of trochanters (vs absence). An unexpected finding of this species on a bird of the family Threskiornithidae (Pelecaniformes) is discussed as an example of host shift. Additionally, a key to the species of the genus is provided.     

Genus <Emphasis Type="Italic">Eckhardites</Emphasis> Mitta (Cardioceratidae,Ammonoidea) from the Lower Callovian of the subboreal Jurassic

The genus Eckhardites Mitta 1999, with the type species Macrocephalites pavlowi Smorodina, 1928 is discussed and its diagnosis and assignment to the family Cardioceratidae are substantiated. Eckhardites is compared to the genus Macrocephalites Zittel (family Sphaeroceratidae), to which some workers presently assign the type species of Eckhardites. Three species of Eckhardites are recorded from the basal Callovian elatmae Zone of the Russian Platform, one of which (E. menzeli (Mönnig)) was originally described from the synchronous beds in Germany. A new species E. dietli sp. nov. is described.     

Host specificity of Asian <Emphasis Type="Italic">Chrysochus</Emphasis> Chevr. in Dej. (Coleoptera,Chrysomelidae: Eumolpinae) and their potential use for biological control of invasive <Emphasis Type="Italic">Vincetoxicum</Emphasis> species

Three Asian leaf beetles of the genus Chrysochus were investigated as potential biological control agents of Vincetoxicum rossicum and V. nigrum, invasive weeds in northeastern North America. Chrysochus chinensis and Ch. globicollis were collected from a field host in a different genus and subtribe. Preliminary no-choice laboratory tests with Ch. goniostoma showed that its physiological host range is too broad. Based on these data, we are not considering these three species as potential biological control agents of invasive Vincetoxicum species.     

First records of the powdery mildews <Emphasis Type="Italic">Erysiphe platani</Emphasis> and <Emphasis Type="Italic">E. alphitoides</Emphasis> on <Emphasis Type="Italic">Ailanthus altissima</Emphasis> reveal host jumps independent of host phylogeny

The tree-of-heaven Ailanthus altissima (family Simaroubaceae, order Sapindales) is one of the most invasive neophytes in Europe. The tree originated in China and became invasive worldwide in areas with Mediterranean to temperate climates. As known from other invasive plants, only a few pathogens have been reported from A. altissima in Europe, and, to date, powdery mildews on it have been unknown in the European region. Recently, two powdery mildews were found on A. altissima during a survey of neomycetes on non-native plants in Switzerland. Because they did not fit with any of the species known to occur on Simaroubaceae in Asia, they were identified by DNA barcoding using sequences of the ITS region of the n-rDNA, revealing them to be the powdery mildews of plane and oak trees, Erysiphe platani and E. alphitoides. This is the first record of E. platani on a host outside the genus Platanus and its family Platanaceae, as well as its order Proteales. In contrast, E. alphitoides has been reported to occur on several host families and orders. Host jumps over great phylogenetic distances—such as across plant families and orders—appear to be quite common in biogeographically novel associations between Erysiphales species and plants. The consequences of such host jumps for identity and taxonomic placement of species are discussed here. It is further questioned whether both pathogens are usable as biological control agents against the tree-of-heaven.     

Diversity of root-endophytic <Emphasis Type="Italic">Trichoderma</Emphasis> from Malaysian Borneo

Trichoderma species form endophytic associations with plant roots and may provide a range of benefits to their hosts. However, few studies have systematically examined the diversity of Trichoderma species associated with plant roots in tropical regions. During the evaluation of Trichoderma isolates for use as biocontrol agents, root samples were collected from more than 58 genera in 35 plant families from a range of habitats in Malaysian Borneo. Trichoderma species were isolated from surface-sterilised roots and identified following analysis of partial translation elongation factor-1α (tef1) sequences. Species present included Trichoderma afroharzianum, Trichoderma asperelloides, Trichoderma asperellum, Trichoderma guizhouense, Trichoderma reesei, Trichoderma strigosum and Trichoderma virens. Trichoderma asperellum/T. asperelloides, Trichoderma harzianum s.l. and T. virens were the most frequently isolated taxa. tef1 sequence data supported the recognition of undescribed species related to the T. harzianum complex. The results suggest that tropical plants may be a useful source of novel root-associated Trichoderma for biotechnological applications.     

An ultrastructural study of spore wall development and septal pores in species of the <Emphasis Type="Italic">Pachyphlodes</Emphasis> (Pezizaceae,Pezizales) lineage,with a description of the new species <Emphasis Type="Italic">Pachyphlodes annagardnerae</Emphasis>

Pachyphlodes (Pezizaceae) is a genus of truffle-like fungi that is distributed across the Northern Hemisphere. These fungi form ectomycorrhizae primarily with trees in the Fagaceae family, and occasionally with other host plants. The genus Plicariella (= Scabropezia) is phylogenetically inferred as an ally of, or within, the Pachyphlodes lineage. Despite molecular phylogenetic analyses that show the close relationships of species in these two genera, morphological differences in ascomata shape and color, spore ornamentation, and ascus shape are profound. Here, we studied spore wall development to better understand affinities within the Pachyphlodes–Plicariella lineages. Electron microscopy studies indicate that the initial spore wall development is similar across six Pachyphlodes species and a Plicariella species, despite striking differences in mature spore ornamentation among species. Ultrastructural analyses reveal that differences in spore ornamentation among Pachyphlodes species are due to unique developmental events at the final stages of spore wall deposition. Septal pore ultrastructure in Pachyphlodes species is similar to other Pezizaceae that have been studied. Molecular analyses of the five species studied indicate that four of them have not been previously described. The new species Pachyphlodes annagardnerae is here described, and the ultrastructural features of species of Pachyphlodes, Plicariella, and other Pezizales are compared and discussed.     

Arbutoid mycorrhizas of the genus <Emphasis Type="Italic">Cortinarius</Emphasis> from Costa Rica

Arbutoid mycorrhizas of Comarostaphylis arbutoides (Arbutoidea, Ericaceae) from neotropical montane forests are rarely described. To date, only mycorrhizal associations with the fungal species Leccinum monticola, Leotia lubrica and Sebacina sp. are known from literature. The genus Cortinarius is one of the most species-rich ectomycorrhizal taxa with over 2000 assumed species. In this study, two sites in the Cordillera de Talamanca of Costa Rica were sampled, where Com. arbutoides is endemic and grows together with Quercus costaricensis. Using a combined method of rDNA sequence analysis and morphotyping, 33 sampled mycorrhizal systems of Cortinarius were assigned to the subgenera Dermocybe, Phlegmacium and Telamonia. Specific plant primers were used to identify the host plant. Here, we present the phylogenetic data of all found Cortinarii and describe four of the arbutoid mycorrhizal systems morphologically and anatomically.     

<Emphasis Type="Italic">Parasitaxus</Emphasis> parasitized: novel infestation of <Emphasis Type="Italic">Parasitaxus usta</Emphasis> (Podocarpaceae)

The world’s sole ‘parasitic’ gymnosperm Parasitaxus usta (Podocarpaceae) is endemic to the island of Grande Terre, New Caledonia. It is a threatened species because of its limited geographic range and progressing habitat fragmentation. Here, we report a novel scale insect outbreak on a Parasitaxus sub-population from Monts Dzumac in the southern part of Grande Terre. The identity of the scale insect was determined through combining morphological and molecular methods. The field collection of scale insects and their secretions from infested Parasitaxus specimens allowed morphological identification of the superfamily Coccoidea. Subsequent genetic sequencing using CO1 markers allowed phylogenetic placement of the wax scale insects to the genus Ceroplastes (Coccoidea, Coccidae), a widespread pest genus. The identified species, C. pseudoceriferus, has not been previously recorded from New Caledonia. As Parasitaxus is already vulnerable to extinction, this new threat to its long-term survival needs to be monitored. Other New Caledonian endemic plant species are potentially at risk of this new species, although it was not observed on Falcatifolium taxoides, the host of Parasitaxus.