Estudo de germinação de algumas espécies de gramíneas (Poaceae) do bioma pampa

Abstract

The Pampa has only 4% of its area protected by Conservation Units, which demonstrates the importance of actions aimed at preserving its characteristics, however, little value given to this biome contradicts its richness and diversity. The Poaceae family is among the most dominant in this biome, 89 genera and 473 native species are found in Rio Grande do Sul. With that, the objective of this study was to analyze the Germination percentage (G), Germination Speed Index (GSI), Average Germination Time (AGT), Average Germination Speed (AGS) of the species Bothriochloa laguroides (DC.)Herter, Eustachys distichophylla (Lag.) Nees, Mnesithea selloana (Hack.) de Koning & Sosef., Paspalum plicatulum Michx, Paspalum urvillei Steud, Piptochaetium montevidense (Spreng.) Parodi, Saccharum angustifolium (Nees) Trin., Schizachyrium microstachyum (Desv.) Roseng, Sporobolus indicus (L.) R. Br. in order to determine the highest and lowest quantitative potential and germination speed of the studied species. The experiment was conducted at Universidade Federal do Pampa and 200 caryopsis of each species werw cultivated in a germination tray, kept in greenhouse, for 21 days, without the use of dormancy breaking methods. Bothriochloa laguroides was the species with the highest G (52%) and IVG (111,408), followed by P. urvillei with G (51%) and IVG (84,970) and S. angustifolium G (48,5%) demonstrating a high quantitative potential for the recovery of degraded areas. The P. plicatulum species showed a lowest G (1,5%) and IVG (1,796), indicating a high dormancy capacity. The P. montevidense species did not show germination in this study, and this result may be due to the period of cultivation, as this is a winter species and the work was carried out in a period of high average temperatures (23ºC/25ºC).