9 research outputs found

    Pyriculariopsis calatheae sp. nov., a novel anamorphic hyphomycete from the Atlantic forest of Brazil causing leaf spots on Calathea longifolia

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    The new species Pyriculariopsis calatheae is described causing leaf spots on Calathea longifolia (Marantaceae). It represents an addition to the mycobiota of the tropical seasonal semi-deciduous montane forest, a component of the Brazilian Atlantic forest and a highly threatened ecosystem

    Condições de ambiente favoráveis à germinação e à infecção de Puccinia substriata var. penicillariae em diferentes cultivares de milheto pérola

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    A ferrugem do milheto (Pennisetum glaucum), causada por Puccinia substriata var. penicillariae, provoca perdas na produção da forragem. Tendo em vista a escassez de informações sobre a doença no Brasil realizou-se o presente trabalho sobre a sua epidemiologia. Avaliaram-se, em casa-de-vegetação, o período latente médio, a freqüência de infecção e tamanho das lesões da ferrugem em quatro genótipos de milheto: ENA 1, Composto II, BRS 1501 e HKP. In vitro, monitorou-se a germinação dos urediniósporos em diferentes temperaturas (10, 15, 20 e 25ºC), na presença ou não de luz. Após isto, avaliou-se o processo de infecção nos genótipos Guerguera, Souna III, BRS 1501 e ENA 1, em câmara de crescimento, utilizando-se 0, 1, 2, 4, 8 e 12 h de molhamento foliar, na presença ou não de luz, e em casa-de-vegetação, nos genótipos ENA 1, Guerguera e Souna III, utilizando-se 3/4, 1, 2, 4, 6 e 8 h de molhamento foliar. O período latente médio da ferrugem do milheto variou entre 10 e 12 dias, e os urediniósporos germinaram em faixa ampla de temperatura, de 10ºC a 25ºC, na presença ou não de luz, com germinação máxima a 17,5ºC no escuro. Nestas condições, os primeiros esporos germinaram com menos de 45 min. e atingiram taxa máxima, 88,2%, em 1,7 h de incubação. Infecções de folhas foram observadas em plantas submetidas a apenas 45 min de molhamento foliar após a inoculação, porém, com efeito benéfico do escuro e do aumento do período de molhamento foliar.The rust caused by Puccinia substriata var. penicillariae in Pearl millet (Pennisetum glaucum) induces yield losses in this forage crop. Considering the lack of information about this disease in Brazil, this research on its epidemiology has been carried out. The mean latency period, the frequency of infection process and size of lesions on four genotypes of pearl millet (Pennisetum glaucum) ENA 1, Composto II, BRS 1501 and HKP were evaluated in the greenhouse. In vitro, the germination of the urediniospores was monitored at different temperatures (10, 15, 20 and 25ºC), with or without light. After this, the infection process was compared for the genotypes Guerguera, Souna III, BRS 1501 and ENA 1, in a growth chamber, with the leaf wetting time of 0, 1, 2, 4, 8 and 12 hours, with or without light, and in greenhouse, on the genotypes ENA 1, Guerguera and Souna III, with the leaf wetting times of 3/4, 1, 2, 4, 6 and 8 hours. A mean latency period for pearl millet rust between 10 and 12 days was shown, and the urediniospores germinated in a wide range of temperatures, from 10 to 25ºC, with or without light, with a maximum germination at 17.5ºC in the dark. In these conditions, the germination of first spores initiated for less than 45 min at a maximum percentage of 88.2%, with 1.7 h of incubation. Leaf infection can also start after 45 min of leaf wetting after inoculation, but there is a beneficial effect of dark and longer leaf wetting time

    A Review on the Challenges for Increased Production of Castor

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    Castor (Ricinus communis L.) is one of the oldest cultivated crops, but currently it represents only 0.15% of the vegetable oil produced in the world. Castor oil is of continuing importance to the global specialty chemical industry because it is the only commercial source of a hydroxylated fatty acid. Castor also has tremendous future potential as an industrial oilseed crop because of its high seed oil content (more than 480 g kg(-1)), unique fatty acid composition (900 g kg(-1) of ricinoleic acid), potentially high oil yields (1250-2500 L ha(-1)), and ability to be grown under drought and saline conditions. The scientific literature on castor has been generated by a relatively small global community of researchers over the past century. Much of this work was published in dozens of languages in journals that are not easily accessible to the scientific community. This review was conducted to provide a compilation of the most relevant historic research information and define the tremendous future potential of castor. The article was prepared by a group of 22 scientists from 16 institutions and eight countries. Topics discussed in this review include: (i) germplasm, genetics, breeding, biotic stresses, genome sequencing, and biotechnology; (ii) agronomic production practices, diseases, and abiotic stresses; (iii) management and reduction of toxins for the use of castor meal as both an animal feed and an organic fertilizer; (iv) future industrial uses of castor including renewable fuels; (v) world production, consumption, and prices; and (vi) potential and challenges for increased castor production

    Diversity of Brazilian Fungi

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    Abstract Knowledge about the Brazilian fungal diversity was, until 2010, recorded in few taxonomy and ecology publications, as well as in a handful of species lists. With the publication of the Catálogo de Plantas e Fungos do Brasil and the continued availability of an online list, it has been possible to aggregate this dispersed knowledge. The version presented here adds 2,111 species names to the 3,608 listed in 2010. A total of 5,719 species of fungi distributed in 1,246 genera, 102 orders and 13 phyla represents a considerable increase over the last five years, when only 924 genera and 78 orders were registered. Basidiomycota (2,741 species in 22 orders) and Ascomycota (1,881 species in 41 orders) predominate over other groups. The Atlantic Rainforest has the largest number of records, with 3,017 species, followed by Amazon Rainforest (1,050), Caatinga (999), Cerrado (638) and Pampa and Pantanal with 84 and 35 species, respectively. The Northeast region has the greatest richness (2,617 species), followed by Southeast (2,252), South (1,995), North (1,301) and Central-West (488 species). Regarding the States of the Federation, São Paulo with 1,846 species, Pernambuco with 1,611 and Rio Grande do Sul with 1,377 species are the most diverse
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