The effect of Sea Water and Temperature on the Germination Behaviour of Crithmum maritimum

Abstract

The seeds of Crilhmum maritimum L. were germinated fioating on various concentrations of sea water up to 50% at constant temperatures of 5, 10, 15, 20, and 25°C and at alternating temperatures of 5 and 15°C, 5 and 25°C, and 15 and 25°C. Significantly higher germination was obtained at alternating than at constant temperature. When two constant temperatures at which no germination occurred were alternated, good germination was obtained. There was reduced germination and increase in time of first germination as sea water concentration increased. In the absence of sea water, high temperature caused not only severe inhibition of germination but also permanent injury to the seeds. The results help to explain the germination behaviour of the species in nature.

Effect of salinity and chemical factors on seed germination in the halophyte Crithmum maritimum L.

“…Sea fennel seeds response to salinity has been reported by Okusanya (1977) and Marchioni-Ortu and Bocchieri (1984). Our results confirmed some of the results of these studies, showing that salinity inhibited germination even at low concentrations.…”

“…Conversely, salt pretreatment did not affect Plantago crassifolia L. seed germination, at any salt concentration (Vicente et al 2004). In our work, germination of sea fennel seeds started on the 18th day of incubation in distilled water, in good agreement with Okusanya (1977). However, our results differed from those of Marchioni-Ortu and Bocchieri (1984), who showed that Sardinian seeds germinated on the 5th day of setting.…”

“…Sea fennel seed germination has been studied by various authors, mainly regarding light requirements (Okusanya 1977;Marchioni-Ortu and Bocchieri 1984;Thanos et al 1991). Results often differed in these studies, suggesting that light requirement depends on the plant biotope (sand hill or rock).…”

“…Two studies have described the effects of salinity on Crithmum maritimum seed germination. Okusanya (1977) found that seeds from southwest England presented a reduced germination rate and an increased time of germination as salinity increased. The author also showed that C. maritimum seed germination could recover after pretreatment with NaCl.…”

Effect of salt on the growth and metabolism of Glycine max

“…Another adaptation to salinity is the increase in succulence, which reduces the concentration of salts in the protoplasm (Ghoulam et al 2002). The greater growth of the roots in comparison with the aerial part is also considered an adaptation to saline stress (Alshamary et al 2004) since it results in an increased surface area for water uptake, thereby preventing dehydration (Okusanya 1977). Salinity reduces the uptake and transport of nitrate (Carillo et al 2005;Surabhi et al 2008;MaaroufiDguimi et al 2011) and, consequently, the assimilation of nitrogen necessary for protein synthesis (Silveira et al 2001;Qu et al 2011).…”