Germination, initial growth, and biomass allocation in three native Cerrado species
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| Data wydania: | 2012 |
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| Format: | Article |
| Język: | eng |
| Źródło: | Repositório Institucional da UnB |
| Download full: | http://repositorio.unb.br/handle/10482/15535 https://dx.doi.org/10.1590/S0100-84042012000200002 |
Streszczenie: | The parameters of germination, initial growth, and biomass allocation of three native plant species of Cerrado (Copaifera langsdorffii, Dipteryx alata and Kielmeyera coriacea) were established. The species had germination percentages above 88% and average germination times longer than 139 hours. The average time for the opening of the first leaf pair was more than 538 hours for all three species. The average root length of C. langsdorffii and D. alata seedlings after 80 days of growth was around 40 cm, four times larger than the average shoot length (< 10 cm), although the root and shoot biomasses were similar for both species. The average root length (> 20 cm) of K. coriacea seedlings was four times larger than the average shoot length (< 5 cm), and the root biomass was 243% greater than the shoot biomass. Increase in seedling biomass was sustained primarily by the cotyledons in C. langsdorffii and D. alata, which acted as reserve organs and showed progressive weight reductions. Increase in seedling biomass in K. coriacea was sustained primarily by photosynthesis, since the cotyledons showed no significant weight reduction, acting primarily as photosynthetic organs. The length of the root systems was at least four times larger than the length of the shoots parts in all three species. Higher investment in root length rather than in root biomass suggest that the initial growth of these species is primarily to ensure access to water resources, apparently putting off the function of the radicular system as storage organ. |