The arrest of development of abortive reproductive organs in the unisexual flower of Vitis vinifera ssp. silvestris
Articolo
Data di Pubblicazione:
2003
Citazione:
The arrest of development of abortive reproductive organs in the unisexual flower of Vitis vinifera ssp. silvestris / E. CAPORALI, A. SPADA, G. MARZIANI, O. FAILLA, A. SCIENZA. - In: SEXUAL PLANT REPRODUCTION. - ISSN 0934-0882. - 15:6(2003), pp. 291-300.
Abstract:
During the first stages of development, flowers
of most dioecious species are hermaphroditic, with their
transition to unisexual flowers being the result of the
developmental arrest of one set of reproductive organs. In
this work, we describe the development of male and
female flowers of the dioecious wild grape species Vitis
vinifera ssp. silvestris through scanning electron microscopy
analysis and cytological observations, focusing our
attention on the transition from bisexual to unisexual
development. We divide floral development of the wild
grape into eight stages. Differences between male and
female flowers appear first at stage 6, when the style and
stigma start to differentiate in female but not in male
flowers. Cytological analysis of the slowly growing
abortive pistil of male flowers shows that megagametophyte
formation is, surprisingly, not inhibited. Instead of
pistil abortion in the male flower, sexual determination is
accomplished through programmed death of external
nucellus cells and some layers of integumentary cells.
Sterility of male structures in female flowers follows a
different pattern, with microspore abnormalities evident
from the time of their release from the tetrad. Sterile
microspores and pollen grains in female flowers display
an abnormal round shape, lacking colpi and possessing
uniformly thickened cell walls that impede germination.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Dioecious flower formation · Programmed
cell death · Sexual differentiation · Unisexual flower
sterility · Vitis vinifera ssp. silvestris
Elenco autori:
E. CAPORALI, A. SPADA, G. MARZIANI, O. FAILLA, A. SCIENZA
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