Changes of sugar contents in different tissues and cell structure in two grape(Vitis vinifera L.) varieties under low temperature stress

【Objective】To study the changes of sugar contents in different tissues and cell structure of twogrape varieties with different cold-resistance under cold stress.【Methods】The pot-cultured cuttings of‘Beta'which is usually ultilized as rootstock with cold-resistance and‘Cabernet Sauvignon'that is oneof the wine grapes with low-temperature sensitivity were used as experimental materials. The changes ofsoluble sugar content,stem anatomic structure and ultra-structure of wine grape organ under low temper-atures were investigated.【Results】‘Beta'and‘Cabernet Sauvignon'adapted to low temperature by in-creasing sucrose contents. The response of the soluble sugar to low temperatures occurred in leaves first,then in stems,and in roots finally. On the anatomic structure of stems,‘Beta'had smaller cell,morecell layers and thicker cuticles,and the starch accumulated earlier and more. However,‘Cabernet Sauvi-gnon'had larger cell,fewer cell layers and thinner cuticles,and the starch accumulated later and less.On the ultrastructure of stems cell,with the increasing of stress duration,‘Cabernet Sauvignon'stemcells suffered more seriously. The chloroplast membrane of‘Cabernet Sauvignon'was broken and the partial chloroplast thylakoid disintegrated and loosed after 6 d low temperature stress. And some organellesdegraded. Multi-membrane structure arranged like concentric circles were found in cytoplasm of partialBeta cell.【Conclusion】In short,there was obvious difference in anatomic structure and ultrastructure be-tween Beta and Cabernet Sauvignon under low temperatures,and the physiological response in solublesugar accumulation of different organ was different as well,which provided the cell evidence for the cold-resistance difference among different grape varieties.