Additions to the genera Asterolibertia and Cirsosia (Asterinaceae, Asterinales), with particular reference to species from the Brazilian Cerrado

Four new Asterolibertia species and a new variety of Cirsosia splendida, all found on native Cerrado plants, belonging to three host families are described, illustrated and named as: A. bahiensis sp. nov. on Erythroxylum sp. (Erythroxylaceae); A. barrinhensis sp. nov. on Diospyros burchellii (Ebenaceae); A. campograndensis sp. nov. on Hirtella glandulosa (Chrysobalanaceae); A. parinaricola sp. nov. on Parinari obtusifolia (Chrysobalanaceae); and Cirsosia splendida var. laevigata var. nov., showing both sexual and asexual morphs, on H. glandulosa and H. gracilipes (Chrysobalanaceae). Finally, A. licaniae is reported on a new host, H. gracilipes. Keys to all the known species of Asterolibertia and Cirsosia are included

Selection of fungi with biocontrol potential against the black spot disease of papaya

The use of fungicides is the main control measure against the black-spot disease of papaya. The biological control is an alternative to that, being the selection of mycoparasitic fungi the first step in programs aiming at this kind of control. This study aimed to obtain and select fungi with potential to the biocontrol of the black spot disease of papaya. For this purpose, 24 isolates were collected from different regions and pathosystems, and then identified morphologically and by the ITS region sequencing. In order to evaluate the mycoparasite potential, two assessments, in a randomized block design, with three replications, were carried out in a shadehouse, being the obtained isolates inoculated on papaya leaves with black spot lesions. The average time for the appearance of mycoparasitism signs and the incidence of mycoparasitized black spot lesions were evaluated. Of the 24 isolates obtained, ten were from Hansfordia pulvinata, two from Lecanicillium lecaniium, two from Simplicillium lanossoniveum, one from Sarocladium implicatum and nine from Acremonium spp. A wide variability, concerning the mycoparasitism on black spot lesions, was observed, especially for the isolates H-611, H-613, H-614 and H-615, which showed the highest colonization averages. The results demonstrate that H. pulvinata has a great potential to be used as a biocontrol agent against Asperisporium caricae

Microbiota for the biological control of invasive Brazilian native plants, Mitrarpus hirtus, Palicourea marcgravii, Pereskia aculeata, Psidium cattleianum and Tradescantia fluminensis

Efetuaram-se levantamentos da microbiota fitopatogênica associada às seguintes plantas daninhas nativas do Brasil: Mitracarpus hirtus (Rubiaceae), Palicourea marcgravii (Rubiaceae). Pereskia aculeata, (Cactaceae), Psidium catleianum (Myrtaceae) e Tradescantia fluminensis (Commelinaceae). Tais levantamentos foram conduzidos em todos os estados do sudeste e sul do país, visando a busca por potenciais agentes de controle biológico destas importantes invasoras. A seleção dos locais a serem visitados para coleta foi feita com base nos registros de ocorrência das plantas-alvo nos principais herbários nacionais e nos dados de clima de cada região. Quando possível, as coletas foram feitas nos diversos tipos climáticos onde a planta-alvo ocorria. Trinta espécies fúngicas, associadas às essas quatro plantas-alvo, foram identificadas. Dentre essas as seguintes novidades taxonômicas: um novo gênero, 15 novas espécies e uma nova variedade. Além disto. dentre os demais fungos coletados, 11representaram novos registros geográfico para o Brasil ou registros de novo hospedeiro para o taxon. Em M. Hirtus, duas novas espécies fúngicas, Cercospora mitracarpi-hirti e Puccinia mitracarpii , destacaram-se como possíveis agentes de biocontrole desta espécie invasora em ambiente exóticos. Somente uma nova espécie de pseudocercospora e uma espécie de ferrugem foram encontradas atacando P. Marcgravii. Nenhum destes parece ter potencial para utilização no controle biológico. Para P. Aculeata, a ferrugem Uromyces pereskiae e uma nova espécie de Pseudocercospora, destacaram-se como potenciais agentes de biocontrole. No entanto, o ciclo de vida de U. Pereskiae necessita de mais estudos para a sua utilização como agente de controle biológico clássico. Para P. Cattleianum, dentre as 9 espécies encontradas, as duas Mycosphaerellaceae, Stenella sp. e Mycosphaerella sp., destacaram-se para o controle biológico dessa planta, reconhecida como responsável por alguns dos piores problemas de invasões biológicas no mundo, particularmente em ilhas oceânicas.A survey of the pathogenic mycobiota of the following weed species native to Brazil was performed: Mitracarpus hirtus (Rubiaceae), Palicourea marcgravii (Rubiaceae). Pereskia aculeata, (Cactaceae), Psidium catleianum (Myrtaceae) e Tradescantia fluminensis (Commelinaceae). This survey was conducted in all states in South and Southeastern Brazil and the principal aim was the discovery of potential biocontrol agents to be used against these weeds. Selection of localities to be visited was made after a compilation of records of occurrences of the target-plants in the main Brazilian herbaria and a study of climatic maps of Brazil. Based on this iinformation it was then attempted to select areas representing the various kinds of climate where the target-plants occur in nature. Thirty fungal species were collected in association with the four target-plant species. Among these the following taxonomic novelties were found: One new genus, 15 new species and one new variety. Moreover, among the other fungi that were collected 11 represented new geographic records for Brazil or new host-pathogen associations. Two new fungal species werw found on M hirtus: Cercospora mitracarpi-hirti and Puccinia mitracarpii. Both are recognized as having potential interest as classical biocontrol agents. Only two fungal species were found attacking P. Marcgravii: a new species of Pseudocercospora and an already known rust species. None seem to have biocontrol potential. Pereskia aculeata, had two fungal pathogens associated whith it that appeared to have potential as biocontrol agents: Uromyces pereskiae and a new species of Pseudocercospora. Nevertheless, before U. Pereskiae ais further considered as a potential biocontrol agent, its life-cycle needs further clarification as only the uredinial and telial stages of this rust seem to be known, contrary to what has been published by other authors. Nine new fungal species were found to have P. Cattleianum as a host. Among these two members of the Mycosphaerellaceae – Stenella sp. and Mycosphaerella sp. - appeared to have good potential as biocontrol agents for this very important weed, which causes some of the worst known biological invasions in the world, particularly in oceanic islandsConselho Nacional de Desenvolvimento Científico e Tecnológic

Morphological and molecular characterization of mycorrhizal fungi from seven Neotropical orchid species

Sete fungos micorrízicos foram isolados de “pelotons” das orquídeas Epidendrum rigidum , Isochillus lineares , Maxillaria marginata , Oncidium flexuosum, Oncidium varicosum, Oceoclades maculata e Polystachia concreta. Todas essas orquídeas são nativas do Brasil, sendo O. maculata de habitat terrestre e as demais epífitas. Três isolados fúngicos foram classificados como Epulorhiza e quatro como Ceratorhiza, ambos pertencentes ao grupo Mycelia sterilia, basidiomicetos similares a Rhizoctonia. O fungo isolado de O. maculata foi classificado como sendo E. repens e os dois outros isolados classificados como Epulorhiza são idênticos entre si e diferenciaram-se das espécies já relatadas para esse gênero, podendo ser considerados como uma nova espécie. Dois isolados classificados como Ceratorhiza são idênticos e provavelmente pertencentes a uma mesma espécie, enquanto os outros dois diferem desses e também entre eles. Assim, esses isolados parecem pertencer a três espécies distintas de Ceratorhiza. Os agrupamentos efetuados após a caracterização morfológica e pelas técnicas moleculares de PCR-RFLP da região ITS do rDNA e de RAPD, foram condizentes. Este é o primeiro relato taxonômico da caracterização morfológica e molecular de fungos micorrízicos isolados de orquídeas brasileiras.Seven mycorrhizal fungi were isolated from pelotons of the orchids Epidendrum rigidum, Isochillus lineares, Maxillaria marginata, Oncidium flexuosum, Oncidium varicosum, Oceoclades maculata and Polystachia concreta. All of these species are Brazilian native orchids. Only O. maculata is a terrestrial species while the others are all epiphytic. These isolates were morphologically classified as Epulorhiza or Ceratorhiza (Mycelia sterilia: anamorphic basidiomycetes) known as Rhizoctonia-like. The isolate from O. maculata was classified as E. repens and the two others isolates belonging to this genus were morphologically identical but distinct from known species of Epulorhiza, and are describing as representing a new species. Two isolates classified as Ceratorhiza are identical and may belong to the same species, while two others appear to belong to two different taxa. So, they can belong to three distinct species of Ceratorhiza. The results of PCR-RFLP from ITS region of rDNA and RAPD analysis are in accordance to the morphological taxonomy. This is the first report of the morphological and molecular characterization of mycorrhizal fungi isolated from Brazilian orchids.Conselho Nacional de Desenvolvimento Científico e Tecnológic