A new endophytic species of Colletotrichum was isolated from an endangered orchid species, Cattleya jongheana in the Parque Estadual da Serra Negra, from the state of Minas Gerais, Brazil. It is described and illustrated as Colletotrichum serranegrense sp. nov. in this study. Morphology and multi-locus phylogenetic analyses based on combined ITS, ACT, TUB2 and CHS-1 sequence data revealed that these isolates were in the Colletotrichum gigasporum species complex and confirmed differences in this compared to other species in this genus.

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Root endophytic fungi are essential to the life cycle of orchids. Many of them act as growth promoters of the host plant and mycorrhizal endophytes are indispensable to seed germination. This study aimed to evaluate the cultivable endophytic fungal richness of five native orchids of rupestrian grasslands (campos rupestres) in Serra do Cipó, Brazil. Healthy roots were sampled and the endophytes isolated, from which total DNA was extracted and the Internal Transcribed Spacer (ITS) region amplified and sequenced. Analysis of 32 fungal sequences permitted the identification of 25 species of the phyla Ascomycota and Basidiomycota. Nine isolates belonged to the Basidiomycota genera Sebacina Tul. & C. Tul. and Tulasnella J. Schröt., which contain important mycorrhizal endophytes of orchids. Same fungal species were obtained from different orchids growing on distinct substrates. Fungal molecular identification indicates high endophyte richness supporting the life cycle of orchids in rupestrian grasslands.

<p>Orchidaceae &eacute; uma das maiores fam&iacute;lias bot&acirc;nicas entre as angiospermas e pelo menos 121 g&ecirc;neros dessa ocorrem no bioma de Cerrado. <em>Oeceoclades maculata </em>(Lindl.) Lindl se desenvolvem em diferentes ambientes e estudos sobre essa s&atilde;o importantes para entendimento de ecologia dessa esp&eacute;cie. Esse trabalho objetivou estudar efeitos da associa&ccedil;&atilde;o micorr&iacute;zica e fatores abi&oacute;ticos sobre desenvolvimento e distribui&ccedil;&atilde;o de <em>O. maculata </em>em sub-bosque de abacateiros. Foram isolados 44 fungos de ra&iacute;zes de <em>O. maculata</em> coletadas em tr&ecirc;s ambientes. Os nove morfotipos obtidos foram testados em experimentos de germina&ccedil;&atilde;o simbi&oacute;tica de sementes de <em>O. maculata</em>. Os morfotipos 1 e 5 mostraram maior efici&ecirc;ncia em promover germina&ccedil;&atilde;o. O talh&atilde;o 18/1995 &eacute; o ambiente que mais propicia o desenvolvimento de <em>O. maculata</em>. Conclui-se que pelo menos nove fungos interagem simbioticamente com <em>O. maculata </em>e que no talh&atilde;o 18/1995 h&aacute; condi&ccedil;&otilde;es que propiciam um bom desenvolvimento dessa<em> </em>pelos fatores bi&oacute;ticos e abi&oacute;ticos.</p>

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The photosynthetic light-response curve reflects the instantaneous response of the net photosynthetic rate to different gradients of photosynthetically active radiation. Genetic materials can respond differently to light and consequently alter productivity. Thus, this work aimed to compare clones of Eucalyptus benthamii and Eucalyptus dunnii by checking the CO2 assimilation rate due to the increase in photosynthetically active radiation. The evaluations were carried out in mini-stumps implanted in a clonal mini-garden system. The CO2 assimilation rate curves were determined with the aid of a portable photosynthesis meter. The curves of CO2 assimilation rate (A) in response to the increase in photosynthetically active radiation (PAR) were evaluated at values of 1500, 1000, 700, 450, 250, 120, 50 and 0 μmol m-2 s-1 for clones of E. benthamii and E. dunnii. The three Eucalyptus clones evaluated showed a similar behavior of the A/PAR curve, showing a high demand for photosynthetically active radiation. In general, the three clones were very similar in terms of CO2 assimilation rate due to the increase in photosynthetically active radiation

In this work, we analyzed the correlation between the canopy coverage of two commercial clones of Eucalyptus benthamii Maiden & Cambage and one of Eucalyptus dunnii Maiden and their shoot yields in a clonal mini-garden system. By canopy coverage, we referred to the area of a picture occupied by leaves (green area) when analyzed using computational resources. The mini-garden was set up to yield shoots on a regular time schedule (between 20 and 30 days) to obtain mini-cuttings for clonal propagation. Pictures were taken at approximately 30 cm above the upper leaves from the plots containing mini-stumps of each clone on the day before the collection of mini-cuttings for six consecutive harvests (approximately 6 months). The leaf coverage was obtained using the computational package Easy Leaf Area. Our results indicated a significantly high Pearson correlation coefficient (r = 0744, P < 0.001) between the canopy coverage and the number of shoots produced by each clone. A logistic regression model was adjusted to this dataset, enabling a prediction of the number of shoots based on the canopy coverage. This approach has the potential for assisting forest nurseries in predicting the yield of mini-cuttings while conducting clonal propagation of their genetic materials.

The main objective of this study was to investigate genetic control for individual volume (VOL) and genetic and phenotypic correlation between trait measured at two different ages. We also assessed three different selection intensities (i=1%, i=5% and i= 10%) to understand the effects on genetic gain and effective size. Eight progeny tests were evaluated included three tests of C. citriodora (CCT), two tests of C. variegata (CCV), and three tests of C. torelliana (CTO). Narrow-sense heritability (h ̂_a^2) ranged from 0.264 to 0.62 for the CCT tests, from 0.07 to 0.21 for the CCV tests, and from 0.14 to 0.69 for CTO. The coefficients of individual genetic variation (CVgi (%)) ranged from 22.5% to 63.9% for CCT, from 19,3% to 28,3% for CCV, and from 22.8% to 41.3% for CTO. Considering a selection intensity of 10%, the Ne after selection would range from 31 to 98 for CCT, 36 to 47 for CCV, and 45 to 62 for CTO. For the TP8two CTO tests, a selection intensity greater than 10% is recommended. With ana selection intensity of 10%, genetic gains ranged from 25 to 107% for CCT, from 14 to 27% for CCV, and from 19 to 64% for CTO