Etude de la sporulation de Gracilaria gracilis (Stackhouse) m. steentoft, L.m. irvine et w.f. farnham et Gracilaria bursa pastoris (S.G.Gmelin) p.c silva de la lagune de Bizerte (Tunisie)

Abstract

Study of carpospore shedding of Gracilaria gracilis and Gracilaria bursa-pastoris was carried out on cystocarpic female gametophyte fragments. These fragments were picked up at different levels (apices; medium parties and basal ones), which reflect the degree of the age of the mother plant. The fragments were exposed to different stress (hydric, thermic and luminous: intensity and photoperiod). The global results showed that the maximum of spore release was generally obtained for 12/12 photoperiod whatever the origin of the fragments on the plant and the intensity of the irradiance and this for especially the first species.