No abstract

A study was conducted to evaluate structural and functional modifications in Diplachne fusca roots under varying regimes of salt stress. Differently adapted populations were collected from ecologically different regions in the Punjab region namely Pakka Anna (hypersaline dryland), Sahianwala (saline waterlogged area), Kalar Kahar (hypersaline salt marsh), Rahimyar Khan (saline sandy loam) and Treemu (saline seasonal inundation). The plants were grown in normal non-saline condition at the University of Agriculture, Faisalabad for 6 months to acclimatize them in the Faisalabad conditions. Three salt stress levels were maintained thereafter, i.e., 0, 200 and 400 mM NaCl for 90 days. All populations responded differently to increasing salt levels. The Pakka Anna population was found to be the most tolerant which relied mainly on increased K + uptake but maintained Ca 2+ uptake in root. An increase in root cross-sectional area was also observed in this population due to increase in storage parenchyma and vascular tissues. This appeared to be crucial towards water conservation in this population. The Sahianwala population collected from saline waterlogged area ranked second in salt tolerance. The notable anatomical modifications in this population included increased vascular tissue and aerenchymatous formation for efficient translocation of nutrients and gaseous exchange especially under anaerobic conditions. It was concluded that differently adapted populations evolved distinctly in geographically isolated regions by development of specific root anatomical features.