SALINITY AND DROUGHT STRESS TOLERANCE OF SOME PLANT SPECIES OF THAR DESERT, PAKISTAN: IMPLICATIONS IN BIO-SALINE AGRICULTURE

Salinity and drought are twin menaces that have major influence on the sustainability of agriculture, especially in rain-fed areas of Pakistan. Therefore, to evaluate the influence of salinity and drought two pot studies were conducted to compare the salinity (study-1) and drought (study-2) stress tolerance of four common indigenous species of desert plants. The species included in both experiments were Prosopis cineraria (Kandi), Acacia senegal (Kumbhat), Salvadora oleoides (Jar) and Tecomela undulata (Rohera). Seeds of all four species were hydro-primed, placed on blotting paper and adjusted in Petri dishes, treated with 0, 0.25, 0.75 and 1.0 % NaCl solution and raised on full strength Hoagland solution. In second study, seeds were placed in plastic trays having 200g acid-washed river bed sand, supplied with Hoagland solution at 5, 8, 12, 16 and 20 % moisture level. Both the experiments were conducted under controlled conditions (25 +/- 2 degrees C temperature and 70 +/- 04% relative humidity) for six weeks. The results obtained from the study indicated that increasing salinity decreased various growth traits and biomass production of all four species. Both salinity and drought stresses enhanced leaf Na+ content in all four species, while the drought stress caused reduction in osmotic pressure and chlorophyll content in green leaves. Nonetheless, wide variation existed among species for their tolerance to salinity S. oleoides > P. cineraria. A. Senegal > T. undulata and drought stress as S. oleoides > T. undulate > P. cineraria > A. senegal. The study concluded that Jar possessed dual potential to tolerate harsh environment caused by salinity and drought, simultaneously and appeared to be the potential plant species for bio-saline agriculture.