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Palynological studies on
five species of Asteraceae
Mbagwu, F. N.*, Chime, E. G. and Unamba, C. I. N.
Department
of Plant Science and Biotechnology, Imo State University,
Owerri, Imo State Nigeria.
*Corresponding author. E-mail:
mbagwu101@yahoo.co.uk.
Accepted
2 July, 2007 |
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Palynological studies on five species of the family
Asteraceae namely Guternbergia nigritiana, Emilia
praetemissa, Vernonia guineensis, Lagera
pterodonta and Chromolena odorata was carried
out. Results obtained from this investigation showed that
the pollen shape is spheroidal in G. nigritiana,
E. praetermissa and C. odorata
while it is elliptic in V. guineensis and L.
pterodonta. The pollen aperture is porate in all except
in L. pterodonta where it is elliptic. The
pollen wall is echinate in all except in C.
odorata where it is smooth. The general appearance of
the pollen grains is circular in G. nigritiana,
E. praetermissa and C. odorata but
longer than wide in V. guinensis and L.
pterodonta. It is therefore likely that the nature of
the pollen grains in these species could be an evolutionary
modification often inherited to determine the mode of
pollination and thereby perpetuate a particular group of
plants. The similarities in structure showed interspecies
relationships and reasons for them to be in the same family
while the differences in structures showed reasons for them
to exist as distinct species.
Key
words: Palynomorphology, pollen grains, structure, taxa,
asteraceae. |
