Ca. Parera et Dj. Cantliffe, DEHYDRATION RATE AFTER SOLID-MATRIX PRIMING ALTERS SEED PERFORMANCE OF SHRUNKEN-2 CORN, Journal of the American Society for Horticultural Science, 119(3), 1994, pp. 629-635
In a test to overcome poor seed germination and seedling vigor of swee
t corn (Zea mays L.) seeds carrying the shrunken-2 (sh2) mutant endosp
erm, primed seeds of two sh2 sweet corn cultivars-Crisp N'Sweet 711 (C
NS-711) and How Sweet It Is (HSII)-were redried at 15,20,30, or 40C an
d 25% relative humidity after solid matrix priming (SMP). The dehydrat
ion rate was significantly lower in 'CNS-711' than 'HSII' at all tempe
ratures. In both cultivars, the drying temperature after SMP was criti
cal for seed performance. Primed seeds with a higher dehydration rate
(dried at 30 or 40C) had better seed vigor, greater field emergence an
d seedling vigor, lower leachate conductivity and imbibition rate, and
a higher respiration rate and glutamic acid decarboxylase activity th
an primed seeds redried at the lower temperatures or control seeds. In
creased incidence of pathogen growth was observed on seeds dried at 15
and 20C relative to those dried at 30 or 40C, probably as a consequen
ce of greater leakage from the seeds at a lower redrying temperatures.
Lack of tolerance to dehydration at 15 and 20C was another factor adv
ersely affecting the seeds redried at low temperature. A more rapid de
hydration rate at a higher temperature after priming sh2 sweet corn im
proved many of the physiological characteristics used to measure seed
quality and the subsequent emergence and vigor of the seedlings under
field conditions.