Morpho-anatomical and physiological adaptations in Leptochloa fusca from different ecological zones

Abstract

Salinity is a major problem that affects the plants worldwide. Leptochloa fusca is a halophytic plant species and also called as kalar grass. Morpho-anatomical and physiological adaptations in Lepochloa fusca was studied under salinity with plants being collected from different ecological zones. The plants were collected from Pakka Anna, Sahianwala, Treemu, Kalar Kahar and Rahimyar Khan and grown for 6 months in Faisalabad under normal conditions. The salinity treatment was given in 5 levels that were 0, 100, 200, 300 and 400 mM NaCl. Different morphophysiological and anatomical modifications under salt stress were observed during the investigation. Pakka Anna, the highly tolerant population, relied on better water use efficiency, low concentration of Na+ in plant organs, elevated K+ and Ca2+ uptake, and accumulation of osmolytes. Anatomically, it showed increased storage water capacity (root area, parenchyma tissue), efficient water conduction (vascular tissue) and high proportion of mechanical tissue. Decreased stomatal area and density can regulate transpiration rate more easily. The second best from Sahianwala depended on turgor maintenance via accumulation of proline and amino acids. Anatomical modifications involved increased dermal, vascular and parenchymatous tissues, which resulted in increased leaf thickness. Leptochloa fusca can easily tolerate 400 mM NaCl. This level adversely affected growth parameters in less tolerant Treemu and Rahimyar Khan populations. Different populations adopted to different mechanisms for the tolerance. This species can be used for future research endeavours like vegetation of saline wastelands and wetlands. Since it is a salt-accumulant, it will prove to be effective for phytoremediation.