| Gracilaria lemaneiformis Bory is an important economic alga used for agar extraction, natural products with important bioactivity, edible market seaweed in some parts of the world as well as efficient bio-filtration.Tetraspores and protoplast are ideal seeds to obtain new plants in G. lemaneiformis cultivation, but they still have some difficults before used in practice.In this study, we optimized the conditions for tetraspore release; using home-made cuttlebone enzyme to produce protoplast of G lemaneiformis thalli; studied the development process of tetraspores; compared and analysised the photosynthesis activity of tetraspore of its different development stage by using a imaging PAM (pulse-amplitude-modulated) measuring system and researched the photosynthesis activity of different colonies of branches by using a Dual-PAM-100measuring system. The result are as follow:The optimal condition for tetraspore release was a combination of temperature (20℃), photon flux density (60μmolm-2s-l) and salinity of the seawater (30%o).Thallus tips produced large number of protoplast, viable protoplasts stained with Nile red under UV fluorescence microscope found they are true protoplasts that removed cell wall.Carpospore or tetraspores germination and growth from G lemaneiformis are as the same trend:one spore→divide to two cells→divide to four cells→holdfast formation→Shoot development from the holdfast→elongation of newly developed shoot from holdfast→development of juvenile plants from spores.PAM-parameters Y(I), Y(II), ETR(I), ETR(II) and Fv/Fm of different colonies of branches changed with a same trend, the parameter values of1st generation branches>2nd generation branches>3rd generation branches. It suggested that the photosynthesis activity of different colonies of branches changed with the same trend.This research was expected to offer theory direction for large-scale planted by people of G. lemaneiformis.All these studies would offer some direction of breeding of Glemaneiformis. |
PDF Full Text Request