Fitopatologia - Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11741
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Item Queirozia turbinata (Phyllactinieae, Erysiphaceae): a powdery mildew with a dematiaceous anamorph(Mycological Research, 2006-05) Liberato, José R.; Barreto, Robert W.; Niinomi, Seiko; Takamatsu, SusumuThe powdery mildew monotypic genus Queirozia was reduced to a synonym of Pleochaeta in 1982. Now, a re-examination of the type material of Queirozia and of two other specimens showed that Queirozia turbinata has a very distinct combination of characters that do not allow its placement within Pleochaeta. It has forked special aerial hyphae, subclavate and predominantly lemon-shaped conidia, and both conidiophores and conidia varying from greyish to yellowish brown (a feature that appears to be unique for this fungus within the Erysiphales). This may represent the first dematiaceous anamorphic powdery mildew known to science. This fungus also has hemiendophytic mycelium, a character considered almost exclusive to the tribe Phyllactinieae. The outer wall surface pattern of wrinkled and turgid conidia of Q. turbinata as observed under the SEM is different from those presented in the literature for this tribe. Molecular analysis showed that Q. turbinata belongs to the tribe Phyllactinieae and is phylogenetic closer to Pleochaeta than to Leveillula or Phyllactinia. It is therefore acknowledged that Queirozia is closely related to Pleocheta but too distinct morphologically from this genus to be accepted as a synonym. Emended descriptions of Queirozia and Q. turbinata are presented.Item The Colletotrichum orbiculare species complex: Important pathogens of field crops and weeds(Fungal Diversity, 2013-06-27) Barreto, Robert W.; Guatimosim, Eduardo; Crous, Pedro W.; Liu, Fang; Cannon, Paul F.; Damm, UlrikeColletotrichum orbiculare causes anthracnose of Cucurbitaceae and is phylogenetically closely related to pathogens of several other herbaceous hosts belonging to the Asteraceae, Fabaceae and Malvaceae. Most of them are known for their hemibiotrophic infection strategy and as destructive pathogens either of field crops or weeds. In order to study the phylogenetic relationships of these fungi, a multilocus analysis (ITS, GAPDH, CHS-1, HIS3, ACT, TUB2, GS) of 42 strains of C. orbiculare and related species was conducted. The analysis resulted in nine clades that confirmed the four species previously known as belonging to this species complex, C. lindemuthianum, C. malvarum, C. orbiculare and C. trifolii, and recognised four new species from weeds, namely C. bidentis, C. sidae, C. spinosum and C. tebeestii. The name C. orbiculare itself is widely used in plant pathology and science, but is invalid according to current nomenclatural rules. Therefore we described a new species with the same epithet and a type specimen that agrees with our current understanding of this species, and is linked to a living culture. Following the recent epitypification of C. lindemuthianum, we chose appropriate specimens with associated strains to serve as epitypes of C. malvarum and C. trifolii, and selected an authentic specimen of C. trifolii as lectotype.Item Queirozia turbinata (Phyllactinieae, Erysiphaceae): a powdery mildew with a dematiaceous anamorph(Mycological Research, 2006-04-17) Liberato, José R.; Barreto, Robert W.; Niinomi, Seiko; Takamatsu, SusumuThe powdery mildew monotypic genus Queirozia was reduced to a synonym of Pleochaeta in 1982. Now, a re-examination of the type material of Queirozia and of two other specimens showed that Queirozia turbinata has a very distinct combination of characters that do not allow its placement within Pleochaeta. It has forked special aerial hyphae, subclavate and predominantly lemon-shaped conidia, and both conidiophores and conidia varying from greyish to yellowish brown (a feature that appears to be unique for this fungus within the Erysiphales). This may represent the first dematiaceous anamorphic powdery mildew known to science. This fungus also has hemiendophytic mycelium, a character considered almost exclusive to the tribe Phyllactinieae. The outer wall surface pattern of wrinkled and turgid conidia of Q. turbinata as observed under the SEM is different from those presented in the literature for this tribe. Molecular analysis showed that Q. turbinata belongs to the tribe Phyllactinieae and is phylogenetic closer to Pleochaeta than to Leveillula or Phyllactinia. It is therefore acknowledged that Queirozia is closely related to Pleocheta but too distinct morphologically from this genus to be accepted as a synonym. Emended descriptions of Queirozia and Q. turbinata are presented.Item A new Inocyclus species (Parmulariaceae) on the neotropical fern Pleopeltis astrolepis(IMA Fungus, 2014-05-09) Guatimosim, Eduardo; Schwartsburd, Pedro B.; Barreto, Robert W.During a survey for fungal pathogens associated with ferns in Brazil, a tar spot-causing fungus was found on fronds of Pleopeltis astrolepis. This was recognised as belonging to Inocyclus (Parmulariaceae). After comparison with other species in the genus, it was concluded that the fungus on P. astrolepis is a new species, described here as Inocyclus angularis sp. nov.Item A new species of the lenticel fungal genus Claviradulomyces (Ostropales) from the Brazilian Atlantic forest tree Xylopia sericea (Annonaceae)(IMA Fungus, 2012-11-15) Barreto, Robert W.; Johnston, Peter R.; Crous, Pedro W.; Evans, Harry C.Claviradulomyces xylopiae sp. nov. is introduced for a fungus occurring in association with abnormal (enlarged, spongy) lenticels of Xylopia sericea (Annonaceae), a common tree of the Atlantic forest and Cerrado ecosystems in Brazil. This is the second species described in the genus and, although it is morphologically distinct from the type species, C. dabeicola from West Africa, it possesses the same characteristics. Apothecial ascomata have periphysoids and paraphyses that are inflated apically (clavate), and ornamented with denticles (raduliform). Furthermore, similar to the type species, it also has long-cylindric or acerose, aseptate ascospores and conidia. An additional asexual morph was produced in culture and is described. Molecular studies of C. dabeicola and the new species confirmed a placement in Ostropales, although a relationship to Odontotremataceae was not supported. Both species were consistently in association with abnormal lenticular development on their woody hosts. It remains to be ascertained, however, if these are the causal agents of the bark disorders, or, simply, opportunistic colonisers. The finding of the second species in the genus Claviradulomyces on a plant from a distantly related family to that of the host of C. dabeicola (Erythroxylaceae) for the genus on a different continent suggests that fungi in this genus may be common on lenticels of other woody plants, and could even have a pantropical distribution. It is possible that fungi in the genus have remained unreported until now because lenticels have remained neglected as a habitat surveyed by mycologists.Item Reappraisal and neotypification of Phyllachora feijoae(IMA Fungus, 2012-04-05) Costa, Lilian C.; Macedo, Davi M.; Barreto, Robert W.Acca sellowiana (Myrtaceae), feijoa (in Brazil, goiaba da serra), is a native southern South America tree that produces edible fruits which, although only occasionally cultivated in South America, became a significant fruit crop in New Zealand. Recently, during surveys for fungal pathogens of feijoa in southern Brazil, several plants were found bearing tar-spot symptoms caused by a species of Phyllachora. A literature search enabled us to identify the fungus as Phyllachora feijoae, a little-known species originally described in the 19th century by H. Rehm and later transferred to the genus Catacauma. The name Catacauma feijoae, although now regarded as a later synonym of P. feijoae is still mistakenly in use (as, for instance, in the Brazilian list of fungi on plants). The type specimen was most probably deposited in the Botanisches Garten und Museum Berlin-Dahlem (B) and lost or destroyed during World War II, and could not be located. The recent recollection of abundant material of this fungus in the vicinity of Pelotas (Rio Grande do Sul, Brazil) allowed its re-examination and neotypification. Phyllachora feijoae is also illustrated here for the first time.