Seed germination strategies of 10 species of native herbaceous plants of the sclerophyllous shrubland in central Chile

Abstract

The relative importance of light and the effect of cold for germination of 10 herbaceous plants native to the shrubland of central Chile was explored. The seeds of each species were assigned to: (1) seeds germinated for three months under white light, no cold was applied, (2) seeds germinated for three months under white light, cold stratification (5 °C) was applied for three months before being sown, (3) seeds germinated in darkness for 30 days, and (4) seeds germinated in light for 30 days. (1) and (2) sown at the same time. Similarly, (2) and (3). Both were compared with Student’s t tests. Five germination variables were evaluated with Principal Component Analysis (PCA). Five species achieved significantly higher germination under light than in darkness. Four species presented significantly higher germination in seeds exposed to cold. The first two dimensions of the PCA explained 79.36 % of the variance, with the first dimension explaining 44.72 %. The first dimension was associated with the light-dependent variable. The second was associated with the cold-dependent variable. The results show that the 10 herbs present some degree of light-dependent germination. However, cold dependence was of negative value for two species. Both variables are inversely correlated, supporting the hypothesis of two potential strategies: (1) associated with the variation of light in space and (2) associated with the variation of temperature in time.