Abstract: 【Objective】The changes of cell structures and photosynthetic characteristics in leaves of three grapes, cultivars ‘Cabernet Sauvignon’(Vitis vinifera L.), rootstock ‘5BB’ (Vitis berlandieri × Vitis riparia), and scion/rootstock combinations ‘Cabernet Sauvignon/5BB’, were investigated under salt stress conditions to offer a theoretical basis and technique reference for selecting salt-tolerant genes in grapevine cultivars, rootstocks and scion/rootstock combinations.【Method】In a pot culture experiment, grapevine plants were treated with NaCl at 0 and 100 mmol•L-1 for 30 d. When the height of grapevines was about 60 cm, chlorophyll contents, gas exchange and chlorophyll fluorescence parameters, and cell structure characteristics in leaves were determined by using spectrophotometer, chlorophyll fluorometer, and observed with microscope and transmission electron microscopy.【Results】Compared with the control, the thickness of epidermis cells, palisade tissue and spongy tissue in leaves of grapevine increased, and thickness ratio of the palisade/spongy tissue reduced under salt stress(100 mmol.L-1 NaCl). Thylakoids became swollen, the length and width of chloroplast increased by 130%-150% and 130%-200%, respectively. Meanwhile, chlorophyll (especially Chl b) content, PSII potential activity(Fv/Fo), maximal photochemistry efficiency of PSII (Fv/Fm) and net photosynthetic rate(Pn) dramatically decreased in leaves of grapevines under salt stress(100 mmol•L-1 NaCl). There was a difference in effect on three grapevines by salt stress. Among them, ‘5BB’ showed a lesser negative effect on cell and chloroplast structures, photosynthetic rate, and PSII photochemical reaction. ‘Cabernet Sauvignon’ in the middle and ‘Cabernet Sauvignon/5BB’ was the largest.【Conclusion】The alterations of mesophyll cell structure and chlorophyll content under salt stress(100 mmol•L-1 NaCl) could led to the deduction of photosynthetic electron transfer efficiency and photosynthetic rate. Rootstock ‘5BB’ exhibited higher salt-tolerance characters which may be beneficial to improve the salt-tolerance of ‘Cabernet Sauvignon’ by grafting on the ‘5BB’.

Key words: grapevine, salt stress, photosynthetic characteristic, cells structure, rootstock