The effect of explant density, temperature and light on rhizome growthin vitroofAlstroemeria

The effects of number of rhizome explants per culture jar and of ranges of temperature, irradiance and daylength on explant growth, were assessed for Alstroemeria in vitro. Increasing explant number from one to five per culture jar produced no significant differences in the number of aerial shoots per explant, whereas an explant number of six produced a significant decrease (P = 0.01). Increases of temperature, in the range 8 to 18°C significantly increased the number of lateral rhizomes and aerial shoots per explant. Root number was unaffected by temperature. Decreases in irradiance from 20 W m-2 to 5 W m'2, and increases in daylength from 8 to 20 h, produced no significant changes in the number of lateral rhizomes, aerial shoots or roots per explant. For good multiplication the requirements for the culture environment were a temperature of 15°C, an irradiance of 5 W m~2 with a daylength of 8 h.