Study On The Basic Physiology Of Salt Tolerance Of Salicornia Bigelovii Torr

Salicornia bigelovii Torr.. is a kind of euhalophyte. Salicornia bigelovii Torr.and Zea mays were treated with NaCl in the present study. We analyzed the performance of the two species under salt-treament. The results we had determined lined as follows: 1.The effects of salt-treatment on the growth situations of Salicornia bigelovii Torr. and Zea maysBoth fresh weight and dry weight of whole plant of Salicornia bigelovii Torr. under 100-600mmol/L NaCl were higher than the control ,300mmol/L NaCl is the optimal NaCl concentrations for Salicornia bigelovii Torr. Both fresh weight and dry weight of Zea mays decreased with the increase of NaCl concentration. The organs of the two species responed in different way to salinity. The ratios of roots and shoots of fresh weight of Salicornia bigelovii Torr. decreased with the increase of NaCl concentration in medium, while the ratios of roots and shoots of fresh weight and dry weight of Zea mays increased with the increase of NaCl concentration in the external medium.2.The effects of salt-treatment on the contents of Na+ , Cl- and K+ in roots and shoots of Salicornia bigelovii Torr. and Zea maysThe contents of Na+ and Cl" in the roots and shoots of the two species increased with the increase of NaCl concentration in the external medium. On the contrary, the contents of K+ decreased. The contents of Na+ in the shoots of Salicornia bigelovii Torr. was obviously higher than that in roots, while the contents of Na+ in roots of Zea mays was higher than that in shoots. c(Na)/c(K) in shoots of Salicornia bigelovii Torr. was higher than that in Zea mays.3.The examination of ion subcelluar localiation status by X-ray microanalysis for the NaCl treatment.The contents of Na+ in vacuoles,cytoplasm and apoplast were measured by X-ray microanalysis. The contents of Na+ in them all increased under salinity. Salicornia bigelovii Torr. and Zea mays transported Na+ mainly into vacuoles, and the ability of Salicornia bigelovii Torr. compartmentalized Na+ into vacuoles was higher than Zea mays. The contents of Na+ in vacuoles of Salicornia bigelovii Torr. were 4.03 times higher than that of cytoplasm under 600mmol/LNaCl and the Na+ in vacuoles of Zea mays were 2.98 times higher than that of cytoplasm under 100mmol/LNaCl. 4.The effect of salt-treatment on the Pn,Fv/Fm and FV/Fo.The photosynthesis rate of Salicornia bigelovii Torr. was enhanced by NaCl and was highest under 300mmol/LNaCl.On the contrary,the photosynthesis rate of Zea mays wasinhibitied by NaCl. The data suggested that the reasons for photosynthesis change of Salicornia bigelovii Torr. and Zea mays under NaCl stress are non-stomatal factors.The Fv/Fm and Fv/Fo of Salicornia bigelovii Torr. increased under 100-300 mmol/L NaCl and decreased under 600mmol/L NaCl. It showed under 600mmol/L NaCl the potential activity and efficiency of primary conversion of light energy of PSII in shoots of Salicornia bigelovii Torr. decreased.5.The effects of salt-treament on the osmotic adjustment ability of Salicornia bigelovii Torr.and Zea maysThe osmotic adjustment ability of the Salicornia bigelovii Torr. was higher than that of Zea mays under the same NaCl concentration. The osmotic adjustment ability of Salicornia bigelovii Torr. was 1.12MPa under 100mmol/LNaCl, while osmotic adjustment ability of Zea mays was only 0.61MPa.6.The effects of salt-treament on the ultrastructure of chloroplast of Salicornia bigelovii Torr. and Zea maysUltrastructure changes of Zea mays and Salicornia bigelovii Torr. chloroplast under salt-stress of various degree(0.100.600mmol/LNaCl) were examineed with transmission electron microscope. The observations showed that no ultrastructure changes occured under 300mmol/LNaCl for Salicornia bigelovii Torr.; but obviously changes came up under 600mmol/LNaCl. The chloroplast membrane was damaged and the thylakoid of chloroplast became swollen. The ultrastructure of chloroplast of Zea mays changed under 100mmol/LNaCl.In short, Salicornia bigelovii Torr. had strong ability to ada...