3, data clearly indicates the existence of high
exodermal cell area and exodermis thickness in H.
Peterson, "
Exodermal Casparian bands: their significance for ion uptake by roots," Physiologia Plantarum, vol.
Compactness of
exodermal and hypodermal layers in the roots can play active role in preventing the collapse of cortex and prove important structural framework for the aereanchyma formation (Seago and Marsh 1989).Anatomical characteristics greatly help in the identification of plant species and cultivars.
In the closely related Oryza sativa, a hypodermis is biseriate with an uniseriate, small-celled
exodermal layer [10, 13] which, like the epidermis, often excises from mature roots [10], leaving the SC as the outer layer of the root.
secundum dealt with plants cultivated in greenhouse conditions, and described roots with five-six layered velamen, exodermal cells with wall thickenings, 10-12 layered cortex, O-thickened endodermis, and 17 protoxylem poles.
The passage cells are small, quadrangular in TS, with dense cytoplasm and interpolated by the other exodermal cells (Fig.
There are some pentagonal and alive passage cells with dense cytoplasm, usually smaller than the other exodermal cells.
Similarly to the velamen, the exodermal thickenings aid in reduction of water loss by root transpiration (Benzing et al.
Collapse of cortex can be prevented through the compactness of exodermal and hypodermal layers in the roots and is also an important structural framework for the formation of aerenchyma.
Thick walled exodermal cells and outer cortical cells seem as enlarge and undergo into one or two cell divisions which are internally paradermal [14].
The thickening of the external cortex cell walls can be homogeneous as in Pycreus macrostachyos (Figure 10--amphibious species), or more intensive in the first cell layer of the external cortex as in Cyperus odoratus (Figure 13--amphibious species), or the internal wall of the
exodermal cells can be thinner than the outer periclinal one, as in Eichornnia paniculata and Echinodorus grandiflorus (Figures 11-12,14--emergent species).
in some
exodermal cells of Rhynehospora spp.: Govindarajalu, 1975).