The release of secondary dormancy by ethylene in Amaranthus caudatus L. seeds
2003
Kępczyński, Jan | Bihun, Magdalena | Kępczyñska, Ewa
Neither ethylene nor 1-aminocyclopropane-1-carboxylic acid (ACC) was able to prevent the induction of secondary dormancy of Amaranthus caudatus at 45°C. Both ethylene (4.5 × 10(-9)–4.5 × 10(-7) M) and ACC (10(-3)–10(-2) M) removed secondary dormancy at 25°C, although ethylene was much more effective. The presence of ethylene for only 10 h was sufficient to remove secondary dormancy in almost all seeds. Incubation of secondary dormant seeds for up to 5 d at 25°C did not change sensitivity to ethylene. The breaking of secondary dormancy by ethylene was prevented by 2,5-norbornadiene (NBD; 1.5 × 10-5(-3) × 10(-4) M), indicating the physiological action of ethylene. Abscisic acid (ABA; 10(-4)–10(-3) M) increased the requirement for exogenous ethylene. It is suggested that secondary dormancy in A. caudatus seeds might be related to insufficient ethylene production associated with an insufficient amount of ACC.
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