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Reproductive biology of henequén ( Agave fourcroydes ) and its wild ancestor Agave Angustifolia (Agavaceae). i. Gametophyte development
Author(s) -
Piven Nickolai M.,
BarredoPool Felipe A.,
BorgesArgáez Ileana C.,
HerreraAlamillo Miguel A.,
MayoMosqueda Alberto,
HerreraHerrera José L.,
Robert Manuel L.
Publication year - 2001
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/3558424
Subject(s) - megaspore , gametophyte , biology , microspore , pollen , meiosis , gametogenesis , botany , double fertilization , stamen , ovule , ovary , agave , mother cells , egg cell , embryo , microbiology and biotechnology , pollen tube , embryogenesis , pollination , genetics , sperm , gene
The pathways of micro‐ and megagametophyte development in Agave fourcroydes (henequén) and A. angustifolia were studied. We used histology and light microscopy to observe anther ontogeny and ovary differentiation in relation to flower bud size. Both species have the same sexual reproductive strategies and gametophyte development that may be divided into three phases: (1) premeiotic, which includes the establishment of the megaspore mother cell and the pollen mother cell; (2) meiotic, the formation of mature microspores and functional megaspores; (3) postmeiotic, which encompasses the development of mature pollen grains and the formation of the embryo sac. A successive type microsporogenesis was found in both species with formation of T‐shaped tetrads and binuclear pollen grains. In vitro germination tests revealed very low pollen fertility. The female gametophyte is formed from two micropylar megaspore cells after the first meiotic division (bisporic type). Male and female gametogenesis occur asynchronously with microsporogenesis finishing before macrosporogenesis. The results so far show that the formation of male and female gametophytes in henequén is affected at different stages and that these alterations might be responsible for the low fertility shown by this species.