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| Publication Type | J |
| Authors | Wijayasinghe, M. M., K. Jayasuriya, C. V. S. Gunatilleke, I. Gunatilleke and J. L. Walck |
| Title | Effect of salinity on seed germination of five mangroves from Sri Lanka: use of hydrotime modelling for mangrove germination |
| Source | Seed Science Research |
| Author Keywords | germination rate halophytes hydrotime model water potential avicennia-marina salt tolerance temperature growth responses halophyte balance light l. |
| Abstract | Mangroves are highly adapted to extreme environmental conditions that occur at the interface of salt and fresh water. Adaptations to the saline environment during germination are a key to mangrove survival, and thereby, its distribution. The main objective of this research was to study the effect of salinity on seed germination of selected mangrove species and the application of a hydrotime model to explain the relationship between water potential of the medium and rate of seed germination. Germination of seeds was examined at 15, 25 and 35 degrees C in light/dark over a NaCl gradient. Germination time courses were prepared, and germination data were used to investigate whether these species behave according to the principles of the hydrotime model. The model was fitted for the germination of Acanthus ilicifolius seeds at 25 degrees C. Final germination percentage was significantly influenced by species, osmotic potential and their interaction at 25 degrees C. Moreover, temperature had a clear effect on seed germination (Sonneratia caseolaris and Pemphis acidula) which interacted with osmotic potential. Only A. ilicifolius seeds behaved according to the hydrotime principles and thus its threshold water potential was -1.8 MPa. Optimum germination rates for seeds of the other species occurred at osmotic potentials other than 0 MPa. The descending order of salinity tolerance of the tested species was Aegiceras corniculatum > Sonneratia caseolaris > Acanthus ilicifolius > Pemphis acidula > Allophylus cobbe, suggesting that the viviparous species (A. corniculatum) is highly salt tolerant compared with the non-viviparous species. The results revealed that seeds of the study species exhibited facultative halophytic behaviour in which they can germinate over a broad range of saline environments. Use of a hydrotime model for mangroves was limited as germination of their seeds did not meet model criteria. |
| Author Address | [Wijayasinghe, Malaka M.; Jayasuriya, K. M. G. Gehan; Gunatilleke, C. V. S.; Gunatilleke, I. A. U. N.] Univ Peradeniya, Dept Bot, Peradeniya, Sri Lanka. [Wijayasinghe, Malaka M.; Jayasuriya, K. M. G. Gehan; Gunatilleke, C. V. S.; Gunatilleke, I. A. U. N.] Univ Peradeniya, Postgrad Inst Sci, Peradeniya, Sri Lanka. [Walck, Jeffrey L.] Middle Tennessee State Univ, Dept Biol, Murfreesboro, TN 37132 USA. Wijayasinghe, MM (reprint author), Univ Peradeniya, Dept Bot, Peradeniya, Sri Lanka.; Wijayasinghe, MM (reprint author), Univ Peradeniya, Postgrad Inst Sci, Peradeniya, Sri Lanka. malakamadhu@gmail.com |
| ISSN | 0960-2585 |
| ISBN | 0960-2585 |
| 29-Character Source Abbreviation | Seed Sci. Res. |
| Publication Date | Mar |
| Year Published | 2019 |
| Volume | 29 |
| Issue | 1 |
| Beginning Page | 55-63 |
| Digital Object Identifier (DOI) | 10.1017/s0960258518000405 |
| Unique Article Identifier | WOS:000459785800007 |
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