Respuesta germinativa y crecimiento de plántulas de Mammillaria magnimamma (Cactaceae) bajo diferentes condiciones ambientales

Germination response and seedling growth of Mammillaria magnimamma were analyzed. Germination percentage and germination velocity of seeds under different conditions were quantified. Treatments included light/ dark conditions, acidity pretreatments and different temperatures. Seeds are photoblastic positive and show a high viability (86%); light requirement decreases as seeds age. Different temperatures during germination resulted in different germination velocities. Pretreatments with chlorhidric acid did not affect seed viability. Seedling growth in greenhouse conditions was studied using a factorial design which included two levels of light intensity, two levels of nutrient availability and two levels of watering frequency. Seedlings are slow growing (between 0.014 and 0.027 g g-1 d-1) and respond positively to an increase in nutrient availability and light intensity.