Germination characteristics of Gymnocalycium monvillei (Cactaceae) along its entire altitudinal range

KAREN BAUK, JOEL FLORES, CECILIA FERRERO, REYES PÉREZ-SÁNCHEZ , M. LAURA LAS PEÑAS, DIEGO E. GURVICH

BOTANY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2017

1916-2790

Germination characteristics are important to understand how species copes with environmentalvariation. The aims of this work were to analyze the effect of different temperatures (25 and 32 ºC), waterpotentials (0, −0.2, −0.4 and −0.6 MPa) and light conditions (light vs. darkness) on the germination of fivepopulations of the cactus Gymnocalycium monvillei along its entire altitudinal distribution. Theexperiments to assess the effects of temperature, water potential and light conditions were performed ingermination chambers, and total germination (%) and mean germination time (T50) were recorded.Germination decreased from higher to lower altitudinal provenances and the effect was much pronouncedunder 32 ºC. For all altitudinal provenances, germination decreased with lower water potential, with thiseffect being more pronounced at 32 ºC. On the other hand, lower altitudinal provenances were lessaffected by lower water potentials than higher provenances. All altitudinal provenances showed very lowgermination under dark conditions. T50 did not vary among altitudinal provenances at a temperature of 25°C but at32 °C, germination was slower at intermediate altitudes. Our results show that germinationcharacteristics differ considerably among altitudinal provenances and seem to be important indetermining the capacity of the species to inhabit such a broad gradient.