The study of male gametogenesis of Taiwania cryptomerioides Hayata
Date Issued
2005
Date
2005
Author(s)
陳淑華
DOI
932313B002039
Abstract
The study of male gametogenesis on
a conifer species endemic to Taiwan,
Taiwania cryptomerioides Hayata
(Taxodiaceae) was done in this article.
With the aids of fluorescent and electron
microscopic observations, the ontogenic
processes in the fertile and sterile
microsporangia are compared, using
the samples collected from Chitou
Experimental Forest and
Yeou-Shoei-Keng Clonal Orchard of
National Taiwan University, Nantou,
Taiwan. Before meiosis, there was no
significant difference in ultrastructure
between the fertile and sterile
microsporangia. Asynchronous pollen
development with various tetrad forms
may occur in the same
microsporangium either of fertile or
sterile strobili. As the meiotic steps
proceeded, the irregular chromosomal
and nuclear behavior was observed in
the sterile microsporangia. This
included: abnormal chromosome
segregation and cytokiness, and
nuclear fusion of the meiotic products.
Moreover, a callose wall was
observable in the fertile dyad and
2
tetrad, but not in the sterile one. After
dissolution of the callose wall, the fertile
microspores were released into the
locule, while some sterile microspores
still retained as tetrads or dyads with
intertwining of exine walls in the
proximal faces. As a result, there was
no well-developed lamellated endexine,
granulate ectexine, or intine in the sterile
microspores. Eventually, the
intracellular structures in sterile
microspores were dramatically collapsed
before anthesis. The present study
shows that the abortion in pollen
development and male gametogenesis
is possibly attributed to the abnormal
chromosome and the absence of the
callose wall.
Subjects
Taiwania cryptomerioides
male sterility
microsporogenesis
male gametogenesis
callose wall
meiosis
SDGs
Publisher
臺北市：國立臺灣大學生命科學系
Type
report
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