Seed germination behavior of Teucrium santae Quézel & Simonneau: a vulnerable and endemic Lamiaceae (Northwest Algeria)

Abstract

As part of the ex-situ conservation of the rare plant species Teucrium santae (Lamiaceae), which is native to Algeria flora, we conducted this study under controlled conditions to determine the optimal circumstances for the germination of its seeds in terms of light, temperature, and water stress. The seeds showed a double dormancy that could be overcome using scarification with sulfuric acid combined with soaking in Gibberellic acid at 1,500 ppm. The seed’s photosensitivity was tested afterward and found to be indifferent. The highest final germination percentage (75%) was obtained at a temperature of 20 °C. The temperature has no significant effect on the velocity coefficient, unlike the initial germination day and the mean germination time which decrease with increasing temperature. On the opposite of the velocity coefficient, water stress results in a tremendous depressive effect on the final germination percentage, initial germination time and mean germination time. The value of –1.2 MPa constitutes the water potential beyond which germination becomes impossible.