Therefore, anatomical responses of cells and tissues due to
action of water-soluble substances or allelochemicals compounds
need to be elucidated and the morphology of seedlings grown in
the presence of a phytotoxin may also yield important information
(Dayan et al., 2000). Very few microscopic approaches at ultrastructural
level have been conducted on allelopathic effects of extracts
or allelochemicals (Chon and Nelson, 2000; Gra˜na et al., 2013). At
this level, by means of electron microscopy, a study showed that
barley´ıs ∼(Hordeum vulgare) hordenine and gramine allelochemicals
produced damage on cell walls, an increase both in size and
number of vacuoles, autophagy, and disorganization of organelles
(Liu and Lovett, 1993). More recently, a study on allelopathic interference
of benzoic acid against mustard (Brassica juncea) seedling
growth showed irregular shaped cells arranged in a disorganized
manner and cell organelles disruption at cellular level (Kaur et al.,
2005). This result indicates that damage to the mustard root at cellular
level was clearly shown by the changes in cell morphology and
internal organization. So far it has never been verified whether the
inhibition caused by allelochemicals released by A. dealbata have
any involvement at the morphological level. The aim of present
work was to determine whether the direct contact with leaves,
pods and seeds of A. dealbata morphologically alters the rootlets
of recipient seedlings of L. sativa L. and Q. saponaria Mol. In this
way, we shall obtain greater understanding of the mechanisms of
action from allelochemicals released by this invasive species.