Epsilon Archive for Student Projects

Abstract

The purpose of this study was; to compare sugar content and composition in buds of four in
Sweden commercially grown grapevine cultivars (‘Kerner’, ‘Regent’, ‘Rondo’ and ‘Solaris’),
at three different vineyards in Scania and try to investigate the relationship between sugar
content and cold hardiness. The concentration of fructose, glucose, sucrose, raffinose and
stachyose was determined in the lower positioned buds, 2-8 and upper positioned buds, 9-14
of the grapevine shoots with high performance liquid chromatography (HPLC).
The cultivar ‘Solaris’ seems to be more cold tender than ‘Kerner’, ‘Regent’ and ‘Rondo’
when comparing the ratio of fructose and glucose to sucrose. This ratio is strongly related to
cold hardiness in Vitis vinifera grapevine cultivars. The ratio increases as the two
monosaccharides fructose and glucose accumulates. No clear difference in the ratio could be
seen between the other cultivars.
Lower positioned buds showed a higher ratio than upper positioned buds, significantly in
more than half of the observations (53.3 %).
Differences between vineyards showed no clear patterns when comparing the ratio. This is
probably because of differences in many cultural practices that may influence cold hardiness
such as choice of rootstock, fertilisation strategy, temperature in the vineyard, and occurrence
of diseases.
No correlation was found between the temperature on the sampling day and the mean
temperature five days preceding sampling and sugar concentration.