Physiological adaptative characteristics of Imperata cylindrica for salinity tolerance

Two populations of cogongrass Imperata cylindrica (L.) Raeuschel], one from the saline regions of the Salt Range and the other from the non-saline regions of Faisalabad were assessed for salinity tolerance on the basis of some key morphological and physiological attributes. It was hypothesized that the tolerant population from the Salt Range must have developed some specific structural modifications, which are responsible for its better survival under high salinities. These adaptive components can be effectively used in modern technologies for improving degree of tolerance of other sensitive crops. The population from the Salt Range markedly excelled the Faisalabad population in terms of growth and physiological attributes measured in this study. The Faisalabad population of I. cylindrica was unable to survive at the highest salt level (200 mM NaCl). The tolerance of the Salt Range population to salt stress was found to be related to high accumulation of organic osmotica, particularly total free amino acids and proline as well as Ca²⁺ in the shoot. The distinctive structural modifications in the Salt Range population were found to be enhanced succulence, well-developed bulliform cells in leaves and smaller stomatal area.