PHYSIOLOGICAL STUDIES ON THE EFFECTS OF DRYING TEMPERATURES ON CORN SEED QUALITY

The effects of drying temperatures on certain physiological parameters associated with germination of corn (Zea mays L.) seed were determined on two commonly grown inbreds. Seed produced on both maternal inbreds Mo17 (intolerant of high drying temperatures) and A632 (relatively tolerant) leached significantly more sugars into water when dried at 50 °C than at 35 °C. Leaching was most pronounced during the first hour. Electrical conductivity of leachate from maternal inbreds Mo17 and A632 was greater for seed dried at 50 °C than at 35 °C. Seedlings grown from embryos of the maternal inbred Mo17 seed dried at 50 °C had significantly lower shoot and root dry weights and percentage germination than did seedlings grown from embryos of Mo17 seed dried at 35 °C. Histochemical light microscopy of Mo17 and A632 embryos showed that the number of starch grains in the embryonic axis was substantially reduced by the high drying temperature. Embryos from Mo17 seed dried at 50 °C contained a carotenogenic pigment. Almos...