The objective of this study was to determine the influence ofconstant (20, 25, 30 and 35°C) and alternating (12 / 12 hours:20:30°C and 20:35°C) temperatureson seed germinationin a cultivated population of Orinoco apple (Solanum sessiliflorum Dunal) in the absense of light. Percentage of germination and germination velocity index (G.V.I.) were evaluated. The 20:35°C and 20:30°C alternating temperatures presented similar germination, 68.7% and 65.5%, and G.V.I., 33.7 and 32.7, respectively. Germination at constant temperature was very much reduced, varying from 0 to 1 %.
Alternating temperature; viability; germination velocity