About grape plant adaptation to autumn and wintering

In Russia, the grapes which combine valuable traits from Vitis vinifera and resistance to low temperature from V. amurensis of East Asia origin, and V. labrusca and V. riparia, both of American origin, are currently growing in popularity. Plant adaptation to wintering is due to complicated internal changes. We studied the effects of wintering (low temperatures and temperature difference) to the physiological condition and metabolism of grape plants after natural and simulated stresses (the forced dehydration and freezing at -25 °С). Nine commercial varieties were examined, namely Kristall (interspecial hybrid of Euro-Amur-American origin) and Bianka (interspecial hybrid of Euro-American origin) of the early ripening; Barkhatnii, Cabernet Sovinyon (Euro-Asian species from West European eco-geographic group) and Krasnostop AZOS, Dostoinii (interspecial hybrids of Euro-American origin) of middle ripening; Cabernet AZOS and Pervenets Magaracha (interspecial hybrids of Euro-American origin), Ag Chakrak (Euro-Asian species from Eastern eco-geographic group) of late ripening. All samples have been planted in the same year, with Kober 5BB used as a rootstock. As indicators, the total water content, free to bound water content, К +, Са 2+ and Мg 2+ concentration, hydrocarbon, protein, nucleic acid and amino acid content, composition and content of organic acids, including ascorbic acid, were estimated in the phloem of annual shoots and in the wintering buds. It was shown that under grape plant transition from a dormancy, the frost resistance in Kristall, Barkhatnii and Cabernet Sovinyon is caused by both high water-retaining capacity of the cytoplasm and the cell membrane stability, whereas in Dostoinii, Cabernet AZOS and Pervenets Magaracha varieties it is mainly due to water retention, and in Krasnostop AZOS and Ag Chakrak varieties a protective effect results mainly from cell membrane stability. In natural and simulated conditions the highest frost resistance was shown in Kristall, Cabernet Sovinyon, Barkhatnii, Cabernet AZOS and Pervenets Magaracha varieties.