A COMPUTER-CONTROLLED SEED GERMINATOR FOR REALISTIC TEMPERATURE RESPONSE STUDIES

Abstract

The construction and operation of a computer-controlled seed germinator that implements realistic diurnal temperature regimens is described. A key feature of the apparatus is the ability to easily program sinusoidal fluctuations that seeds experience in the soil rather than the square waves typical of many germination cabinets. The apparatus consists of 16 independently-controlled, 25 cm-tall insulated aluminum germination chambers that each hold up to 15 plastic Petri dishes. When programmed for a gradual diurnal fluctuation in temperature, the chamber has little variation in temperature regimen from the center to the top or bottom of the chamber, with a small phase shift in the time when the minimal and maximal daily temperatures occur. Thus, five treatments with three replicates can be placed in each chamber, providing the ability to conduct a five species×16 temperature regimen experiment