Relazioni ormonali nello sviluppo dell'ovario delle orchidee i. effetto in vivo del trattamento con auxine

Abstract

HORMONAL RELATIONS IN THE DEVELOPMENT OF ORCHID OVARY. I. - THE EFFECTS OF TREATMENTS WITH AUXINS ON THE INTACT PLANT. — The flowers of different species of Orchids have been treated with auxins, pure or in solutions, and with pollen from the same or a different species. The auxin treatment consistently induces the elongation of the column and the growth of the ovary. The treatment with the most active of the auxins used (pure NAA) induces necrosis of the column; in this case, growth of the ovary can last for more than one year, till ripening of the fruit. Morever, the interruption of development at any stage, is more frequent.

The stimulation of the ovary can be obtained also with the introduction of auxin into wounds at the basis of the column. In Zygopetalum NAA induces parthenocarpy but not adventive embriony which is induced with exogenous pollen.