SEED-GERMINATION AND SALINITY TOLERANCE IN PLANT-SPECIES GROWING ON SALINE WASTELANDS

Seven plant species including three chenopods, Suaeda fruticosa, Kochi a indica, Atriplex crassifolia and four grasses: Sporobolus arabicus, Cynodon dactylon, Polypogon monspeliensis, Desmostachya bipinnata, var ied greatly in their seed germination and growth responses to soil moi sture or salinity. The germination percentage of each species was sign ificantly lower at soil moisture level of 25% of water holding capacit y than at the levels ranging from 50 to 125%. Increase in salinity res ulted in gradual decrease in seed germination of each species. Growth responses of species to salinity varied widely from significant decrea se with slight salinity to stimulation up to salinity levels of 20 dS m(-1) Higher K+/Na+ ratios in plant shoots of all species compared to that in the root medium indicated selective K+ uptake. Higher toleranc e in chenopod species seems to be attendant on their ability for inter nal ion regulation.