Effect of LiCl on compression and tension properties ofPophyra perforata tissue

Abstract

The mechanical properties of various differentiated regions of thePorphyra perforata thallus and the effect of LiCl were studied by performing compression and tension tests. Among the various differentiated tissues, the holdfast area was high in its ‘compressive modulus of elasticity’ and ‘tensile modulus of elasticity’, possibly related to its thick matrix. Vegetative non-dividing tissue and vegetative dividing tissue were the most flexible and strong, showing the highest ‘percentage elongation at break’ and ‘tensile strength’. The patch area, which is a transition zone leading to sexually mature tissue, had moderate values of tensile properties. Meanwhile, sexually differentiated male and female tissues had the highest ‘compressive modulus of elasticity’ and lowest tensile properties. Thes tisues tended to crumble easily. Treatments in LiCl, as used for DNA extraction, resulted in a decrease in both ‘compressive modulus of elasticity’ (87%) and ‘tensile modulus of elasticity’ (54%). After treatment of tissue for chromosome staining in a method using LiCl, there was a marked decrease in ‘tensile modulus of elasticity’ (49%), while the ‘compressive modulus of elasticity’ remained unchanged. Such mechanical changes verify the softening effect of LiCl on the seaweedP. perforata tissue.