Rc. Brown et Be. Lemmon, Sporogenesis in eusporangiate ferns: I. Monoplastidic meiosis in Angiopteris (Marattiales), J PLANT RES, 114(1115), 2001, pp. 223-235
This is the first report of monoplastidic cell division in ferns. Angiopter
is (Marattiales) undergoes the more primitive form of monoplastidic meiosis
, while other ferns have evolved the polyplastidic type typical of seed pla
nts. In monoplastidic cell division, the single plastid divides and serves
as site of the microtubule organizing center (MTOC) for spindle formation r
esulting in coordinated division of plastid, nucleus, and cytoplasm. In pla
nts with polyplastidic cell division, the MTOC is diffuse and generally per
inuclear. Monoplastidic cell division is seen as a plesiomorphic feature th
at was inherited from algal ancestors containing a single plastid and modif
ied through evolution. Monoplastidic meiosis occurs in all groups of bryoph
ytes (although in only a few hepatics), Isoetes, Selaginella, certain gener
ic segregates of Lycopodium, and in members of the Marattiales. It is not k
nown to occur in psilophytes, Equisetum, leptosporangiate ferns, or seed pl
ants.