Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Seed germination and salinity tolerance in plant species growing on saline wastelands.

Abstract

Seeds of Suaeda fruticosa, Kochia indica, Atriplex crassifolia, Sporobolus arabicus, Cynodon dactylon, Polypogon monspeliensis and Desmostachya bipinnata were germinated for 20 days on filter paper in Petri dishes at salinity levels of 3-40 dS/m. The salinity treatments were made by adding NaCl, Na2SO4, CaCl2 and MgCl2 in the molar ratio 4:10:5:1 to Hoagland solution, which was added to all treatments daily. The seedlings were transferred to pots of acid- and water-washed gravel saturated with Hoagland solution and after 2 weeks, the pots were subjected to salinities of 3-50 dS/m. The species differed greatly in their seed germination and growth responses to substrate moisture or salinity. The germination percentage of each species was significantly lower at a substrate moisture of 25% of water holding capacity than at 50-125%. Increase in salinity resulted in gradual decrease in seed germination of each species. Growth responses of species to salinity differed widely from a significant decrease with slight salinity to stimulation up to salinity levels of 20 dS/m. Higher K+:Na+ ratios in shoots of all species than in the substrate indicated selective K+ uptake. Higher salt tolerance in S. fruticosa, K. indica and A. crassifolia was explained by their ability for internal ion regulation.