Pastoral plants for rehabilitation of degraded soil in Tunisia: the case for use of Calicotome villosa and Genista spachiana (Fabaceae)

Abstract

Calicotome villosa and Genista spachiana are classified as vulnerable in Tunisia and they are of great interest for the  rehabilitation of degraded ecosystems, food for goats and camelids, and for the use of its essential oils in phytotherapy. The aim of this study was to examine the  germination characteristics of both species through analysis of the effects of the salt stress and water stress on germination. We monitored and evaluated different germination characteristics (germination percentage, mean time to germination and germination speed) in the presence of the salt and water stress. Calicotome villosa and Genista spachiana can withstand salinity of up to 15 g/l of salt (31–37% germination at 15 g/l) and also tolerate large doses of PEG₆₀₀₀ (30–40% germination at –1.6 MPa: Polyethylene glycol (PEG) is a hydrophilic polymer). The tolerance of the two species to salinity and water stress allows them to be a source of food for goats and camelids during drought.