Evaluation of the Physiological Response of Ornamental Summer Season Annuals to Salinity Stress

Abstract

Over the past several decades, the southwest zone of Punjab is encountering various problems such as waterlogging, high use of surface canal water for irrigation and swift rise in water demand lead to stagnation in saline zone due to salinity ingression. Due to salinization, most of crops failed to grow, therefore, identification of salt tolerant plants and to check the level of tolerance to salinity in order to prevent mortality plants in salt affected areas is highly required for environment sustainability. To understand these salinity issues, the present study was conducted at Punjab Agricultural University to screen four ornamental summer season annual species suitable for salt affected areas of Punjab. Selection of plant species was done on the basis of physiological changes in plant leaves. The one month old seedlings of four different annual species were grown in 8 inch earthen pots were exposed to five different concentrations of sodium chloride salinity stress (control, 30, 60, 90, and 120 mM). The factorial completely randomized block design was followed in the experiment with three replicates in each treatment. The physiological parameters viz., chlorophyll, carotenoid, relative leaf water content, electrolyte leakage and proline content were calculated to depict the salt tolerant ornamental summer season annual species. It has been concluded on the basis of physiological response, the maximum salt tolerance was observed in P. grandiflora followed by B. scoparia, T. erecta  and Z. elegans.