Structural and functional plasticity in the root and stem of dichanthium annulatum (FORSSK.) stapf under salt stress

Naturally grown populations of Halophytic grass Dichanthium annulatum were collected from saline habitats for the evaluation of structural and functional adaptations in saline soils. Different populations of D. annulatum showed various adaptations i.e. decreased shoot length and shoot fresh weight, increased root length and root fresh weight in highly saline habitats. Increased epidermal thickness and cell area, enlarged storage parenchyma, broader metaxylem vessels, enhanced pith and phloem area observed in roots of highly saline populations. Thickest stem, well developed metaxylem vessels and broader cortical region was seen under severe salinity. Accumulation of organic osmotica i.e. Glycine betaine, proline, total soluble sugars and total soluble proteins contributed significantly to endure harmful consequences of saline conditions. This grass exhibited increased uptake of toxic ions like Na+, Cl- which is very harmful for growth under salt affected habitats. (author)