In this study the germination characteristics of Zannichellia palustris L. subsp, pedicellata (Wahlemb. et Rosen) Hegi seeds collected from a population along the margin of the Orbetello Lagoon (Tuscany, Italy) was examined. The effect of variations in duration of seed after-ripening and environmental parameters such as light, temperature and culture medium salinity on germination was assessed, In addition, germination ability of seeds subjected to stratification (+4 degrees C for 30 days) and differing in morphology was evaluated. A constant temperature of 20 degrees C was optimal for germination, while alternating temperatures of 10/20 and 20/30 degrees C were highly unfavourable and frequently produced no germination. Darkness inhibited germination but this was overcome by a period of stratification. At 20 degrees C seed germination showed a sinusoidal trend linked to seasonal changes. A dimorphism in Z. palustris achenes was observed, Such achenes were also found to differ in germination response, The pronounced control over germination exerted by this species could represent one of its main survival strategies, allowing reproduction in unstable environments characterized by variations in salinity such as were observed in the area under investigation.
The germination characteristics of a population of Zannichellia palustris subsp pedicellata
LOMBARDI, TIZIANA;Bedini S;ONNIS, ANTONINO
1996-01-01
Abstract
In this study the germination characteristics of Zannichellia palustris L. subsp, pedicellata (Wahlemb. et Rosen) Hegi seeds collected from a population along the margin of the Orbetello Lagoon (Tuscany, Italy) was examined. The effect of variations in duration of seed after-ripening and environmental parameters such as light, temperature and culture medium salinity on germination was assessed, In addition, germination ability of seeds subjected to stratification (+4 degrees C for 30 days) and differing in morphology was evaluated. A constant temperature of 20 degrees C was optimal for germination, while alternating temperatures of 10/20 and 20/30 degrees C were highly unfavourable and frequently produced no germination. Darkness inhibited germination but this was overcome by a period of stratification. At 20 degrees C seed germination showed a sinusoidal trend linked to seasonal changes. A dimorphism in Z. palustris achenes was observed, Such achenes were also found to differ in germination response, The pronounced control over germination exerted by this species could represent one of its main survival strategies, allowing reproduction in unstable environments characterized by variations in salinity such as were observed in the area under investigation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
