versión On-line ISSN 0717-6643
GUERRERO, Pablo C; SANDOVAL, Ana C y LEON-LOBOS, Pedro. The effect of chilling on seed germination of placea species (Asparagales: Amaryllidaceae), an endemic genus to central Chile. Gayana Bot. [online]. 2007, vol.64, n.1, pp.40-45. ISSN 0717-6643. http://dx.doi.org/10.4067/S0717-66432007000100005.
The effect of chilling on germination was examined for six Placea species, a genus in the Amaryllidaceae endemic to the Andes and Coastal Range of central Chile. Based on their natural environment, we hypothesized that low temperatures would be important for germination in theses species. We addressed two questions (i) do Placea seeds require chilling for seed germination? (ii) if they required chilling, does thermal history before chilling affect their responsivity to chilling? At 4ºC seeds of all species germinated faster and to a higher level than at 25ºC. After 28 days, when seeds held at 25ºC were moved to 4ºC, germination increased significantly, however at the end of the assay, their germination was still lower than those seeds initially at 4ºC. Thus, Placea seeds required chilling for germinate. Seeds of Placea species might have physiological dormancy or might be non-dormant but with narrow and low range of temperature that are optimal for germination
Palabras clave : Seed physiology; dormancy; biodiversity.