Spartidium saharae is an endemic species of the Saharo-Arabian region. It is a tall shrub widely distributed in many sandy habitats including desert dunes and sandy systems in south-western part of Tunisia, where water and salinity are serious constraints. Laboratory experiments were carried out to assess temperature and salinity effects on seed germination. The seed germination responses were determined in complete darkness over a wide range of temperatures and salinities. Germination was inhibited by either an increase or decrease in temperature from the optimal temperature range (15-20°C). Highest germination percentages were obtained under nonsaline conditions and an increase in NaCl concentrations progressively inhibited seed germination. An interaction between salinity and temperature yielded no germination at 200 mm NaCl.

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As typical arid vegetation, Calycotome villosa is an annual herb playing an important role in folk medicine. In this research, the influences of temperature and salinity on germination of C. villosa seeds gotten from southern Tunisia were investigated. The germination responses of the seeds in total darkness were determined over an extensive array of temperatures (5, 10, 15, 20, 25, 30, 35 and 40°C) as well as salinities (0, 50, 100, 150, 200, 250 and 300 mM NaCl). Seeds of C. villosa were able to germinate at temperatures between 5 and 40°C. Temperatures between 20 and 25°C seemed favorable to germinate these species. The minimum temperature beyond which no germination is expected was 0°C. Utmost germination percent were gotten in non-saline situations as well as arise in NaCl absorptions increasing repressed germination of seed. The rate of growth reduced with arises in salinity on all temperatures. Salt stress decreased both the percentage and the rate of germination. Percent of germination reduced with growing salinity and sternly restricted at 250 and 300 mM. Findings from this research might function as valuable information for C. villosa habitat establishment and renovation plans.

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