Autonomous endosperm induction by in vitro culture of unfertilized ovules of Viola odorata L.

Autonomous endosperm was found in unfertilized ovules of V odorata L. cultu red on MS medium supplemented with 2,4-D as a sole growth regulator or on m edia with 2,4-D and BAP or kinetin, Frequency of endosperm induction was ap proximately 9% in ovules analyzed. The induction rate depended mainly on ge notype of the donor plant, and to lesser degrees, on floral stage, flower s eries and medium type. Multinuclear endosperms consisting of 10-37 nuclei w ere found in ovules after as few as 4 days of culture. In some ovules at th is stage, the egg cell and two polar nuclei were present. The process of en dosperm degeneration began after 3 weeks of culture. In some ovules, degene rating autonomous endosperm was observed up to the 7th week. Parthenogeneti c development of egg cells or apogamy did not accompany autonomous endosper m, supporting the hypothesis of independent pathways for embryo and endospe rm development.