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| Kolb,Rosana Marta; Pilon,Natashi Aparecida Lima; Durigan,Giselda. |
| Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i) recently collected seeds and seeds after six months storage, ii) under constant and alternating temperatures, and iii) in the presence and absence of light. Germinability, mean germination time (MGT) and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conservation; Grasslands; Poaceae; Savanna; Seed storage; Seed viability. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000100087 |
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| Silvestre,Daniel Moreto; Kolb,Rosana Marta; Frei,Fernando; Santos,Catarina dos. |
| We evaluated the phytotoxic effects that the hexane, ethyl acetate and methanol extracts from leaves and branches of the species Turnera ulmifolia L. and Turnera diffusa Willd. ex Schult. (Turneraceae), at concentrations of 1.25, 2.50, 3.75 and 5.00 mg ml-1, have on seed germination and seedling development in cucumber (Cucumis sativus L.). None of the extracts tested prevented germination, although the ethyl acetate extracts of T. diffusa, at 3.75 and 5.00 mg ml-1, reduced the mean germination speed and time to germination. Hexane extracts of both species reduced the main root length, number of secondary roots and hypocotyl length. In the ethyl acetate and methanol extracts, the number of secondary roots and hypocotyl length varied by species and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allelopathy; Cucumis sativus; Germination; Development. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000300003 |
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| Rossatto,Davi Rodrigo; Kolb,Rosana Marta. |
| Gochnatia is very common in different phytophysiognomies in the Cerrado of São Paulo State, occupying open and closed areas. In this study, we compared the leaf anatomy and some ecophysiological traits of two species of Gochnatia, one a shrub (Gochnatia barrosii Cabrera) and the other a tree (Gochnatia polymorpha (Less.) Cabrera), which both occur in an area of "cerradão" at the Estação Ecológica de Assis, SP. We found qualitative structural differences between the species, with G. barrosii presenting amphistomatic leaves with a uniseriate epidermis and G. polymorpha showing hypostomatic leaves and a multiple epidermis or hypodermis on the adaxial surface. Moreover, the G. barrosii leaves had lower values in tissue thickness (with the exception of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado; Gas exchange; Leaf anatomy; Stomata. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062012000400014 |
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