The physiology of dormancy in potato tubers and its relations with the hormonal mechanism of tuberization
THE PHYSIOLOGY OF DORMANCY IN POTATO TUBERS AND ITS RELATIONS WITH THE HORMONAL MECHANISM OF TUBERIZATION. Dormancy* is a particular physiological state in which the buds of potato tubers does not germinate owing to internal factors even though they are placed under optimal environmental conditions....
Guardado en:
| Autor principal: | |
|---|---|
| Formato: | Artículo revista |
| Lenguaje: | Español |
| Publicado: |
Facultad de Ciencias Agropecuarias
1982
|
| Materias: | |
| Acceso en línea: | https://revistas.unc.edu.ar/index.php/agris/article/view/905 |
| Aporte de: |
| Sumario: | THE PHYSIOLOGY OF DORMANCY IN POTATO TUBERS AND ITS RELATIONS WITH THE HORMONAL MECHANISM OF TUBERIZATION. Dormancy* is a particular physiological state in which the buds of potato tubers does not germinate owing to internal factors even though they are placed under optimal environmental conditions. The length of the dormant period is relatively insensible to environmental factors, but it is correlated with high levels of the β inhibitor-complex and with a very low activity of endogenous gibberellins and cytokinins in the periderm and the buds. On the contrary, the end of this period coincides with a sharp decrease of the inhibitor and with a drastic increase in the levels of those phytohormones. The mechanism through which the inhibitor-complex (whose principal component is abscisic acid (ABA)) controls dormancy is not well established. Recent evidence shows that ABA inhibits DNA and RNA synthesis in the buds of dormant tubers. The inhibitor also interferes the synthesis of α-amylase and other hydrolitic enzymes. It also acts as an uncouplant factor for oxidative phosphorylation. Nevertheless, it has been also put in evidence that none of the inhibitors (β-complex or ABA) stimulate tuberization in sprout sections cultured in vitro. Moreover, under favorable photoperiodic conditions (short-days) or unfavorable ones (long-days or continuous light) for tuberization, the foliage synthesizes similar high levels of the inhibitor-complex which seems to be translocated to the periderm of growing young tubers where it gradually accumulates. When the concentration of the inhibitor rises above a certain level, the tubers are dormant. |
|---|