Effect of Temperature and Salinity on the Germination of Lagurus ovatus L.

Abstract

Lagurus ovatus is an annual grass typical of sandy coastal soils, wide-spread in southern Europe. The color and texture of the inflorescence have such features that give good qualities as dry flower. In this work we have studied the germination capacity of Lagurus ovatus in different conditions of temperature, light and salinity. Seeds harvested in of the province of Murcia (Southeast of Spain) were tested in germination chambers with constant temperatures (5, 10, 15, 20, 25 and 30 °C) and combined temperatures (20/30, 15/25, 10/20 and 5/15 °C). For each treatment, the photoperiod was 12 hours and total darkness. The results showed that total darkness was required to germination and the highest germination were obtained with constant temperatures of 10°C (90%) and 15°C (66%). Temperatures above or below reduced significantly the final germination. With alternate temperatures, the highest values were recorded when at least for 12 hours the temperature was 10 °C or 15 °C (5/15, 10/20 and 15/25 °C) 87%, 93%, and 88% respectively. Once calculated the optimum temperature a salinity experiment was carried out to determine how this parameter affected germination. The assay was carried out at 10/20 °C. The seeds were watered with a NaCl2 solution of: 0, 2.5, 5, 7.5, 10, 12.5, 15 and 17.5 dS·m-1. The greatest germination was obtained in non-saline control (88%) and its was linearly reduced with increases in salinity to 10 dS·m-1 (4%). No germination was registered from 12.5 to 17.5 dS·m-1. When non-germinated seeds were transferred to distilled water after the exposure to salinity, rates of germination were very high in all cases. This work was supported by the CICyT of Spain (project AGL2000-0521).