ABSTRACT. The palm tree juçara (Euterpe edulis Mart) is considered one of the most important and threatened native species in the Atlantic Forest. The search for juçara seeds (Euterpe edulis Martius) has increased, generating a need for technologies favorable to their production, quality and conservation. The aim of this study was to describe the seed germination patterns of 45 juçara accessions by using a nonlinear model to examine the behavior of these patterns and select superior genotypes. After clustering 45 juçara accessions into four groups, four nonlinear models, namely, the logistic, Gompertz, von Bertalanffy and Weibull models, were tested based on their fit for each group of accessions. The Gompertz model presented the best fit to describe the germination growth curve of E. edulis seeds. Groups 3 and 4 presented the highest daily germination rates and were considered the most vigorous. Analysis of deviance was performed, revealing genetic variability among the genotypes in terms of seed germination and vigor. It was possible to find a nonlinear model that best explained our data, and this model may also be a promising model for other palm tree species. It is possible to select genotypes based on the characters we analyzed, due to the elevated genetic variability.

The success of the germination process depends on the entry of water through the tissues that enclose the embryo. The presence of salts reduces the gradient between the ground and the surface of the seed, restricting the absorption of water by the seed. The objective of the experiment was to evaluate the effect of salinity and temperature on the germination of carrot seeds. The osmotic potentials utilized in the solutions were 0.0 (control); -0.4; -0.8; -1.2, -1.6 and -2.0 MPa. obtained with the use of NaCl p.a.; the temperatures used were 15 °C, 20 °C, 25 °C, 35 °C, 15-35 °C and 25-35 °C. A commercial variety of carrot seeds, the 'Brasilia' cultivar, was used. Percentage germination, germination speed index, fresh and dry mass of seedlings were determined. The averages were subjected to analysis of regression. Germination was reduced by the temperature of 35 °C and by osmotic potentials greater than -0.8 MPa. Temperatures of 20 °C and 25 °C are more favorable to the germination of seeds in the GSI salt conditions tested.

El éxito en el proceso de la germinación depende del agua que ingresa a través de los tejidos que rodean la semilla. La presencia de sal reduce el gradiente entre el suelo y la superficie de la semilla, lo que limita la absorción del agua por la semilla. El objetivo de la investigación fue evaluar el efecto de la salinidad y la temperatura sobre la germinación de semillas de zanahoria. El potencial osmótico utilizado en las soluciones fue 0,0 (control); - 0,4; -0,8; -1,2, -1,6 y 2,0 Mpa, obtenidas con el uso de NaCl, y las temperaturas utilizadas fueron 15 °C 20 °C 25 °C 35 °C 15-35 °C y 25- 35 °C. En las evaluaciones, se utilizó un lote comercial de Brasilia. En las evaluaciones de semillas de zanahoria cv se midieron porcentaje de germinación, índice de velocidad de germinación, peso fresco y seco de las plántulas. Las medias fueron sometidos a análisis de regresión. En el ensayo, la germinación se redujo en 35 °C en potencial osmótico mayor que -0,8 MPa. Las temperaturas de 20 °C y 25 °C son más favorables para la germinación y la tasa de germinación de las condiciones ensayadas.