Effect of temperature and cold stratification on seed germination of the Mediterranean wild aromatic Clinopodium sandalioticum (Lamiaceae) |
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Authors: | E Mattana R Picciau S Puddu A Cuena Lombraña G Bacchetta |
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Institution: | 1. Centre for the Conservation of Biodiversity (CCB), Department of Life and Environmental Sciences, University of Cagliari, Italy;2. Natural Capital and Plant Health Department, Royal Botanic Gardens, Kew, UK |
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Abstract: | A germination study was carried out on seeds of Clinopodium sandalioticum (Bacch. & Brullo) Bacch. & Brullo ex Peruzzi & Conti (Lamiaceae), a wild aromatic plant endemic to Sardinia. Seeds were incubated at a range of constant (5–25°C) and an alternating temperatures regime (25/10°C), with 12 hours of irradiance per day. The results achieved at 10°C were also compared with those obtained after a period of cold stratification at 5°C for three months. Final seed germination ranged from ca. 28% (5°C) to ca. 72% (25/10°C). A base temperature for germination (Tb) of ca. 5°C and a thermal constant for 50% germination (S) of 89.3°Cd were identified and an optimal temperature for germination (To) was estimated to be comprised between 20 and 25°C. Cold stratification negatively affected seed viability and germination at 10°C. Although a typical “Mediterranean germination syndrome”, could not be detected for C. sandalioticum seeds, these results were coherent with those previously reported for other Mediterranean Lamiaceae species. |
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Keywords: | Base temperature cold stratification endemic germination rate Mediterranean climate |
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