The Relationship between Carbohydrates and Flower Bud Hardiness among Three Forsythia Taxa

Abstract

<jats:p>The accumulation of total soluble sugars (TSS) and starch and their relationship to flower bud hardiness were studied in three <jats:italic>Forsythia</jats:italic> taxa: <jats:italic>Forsythia ×intermedia</jats:italic> `Spectabilis', <jats:italic>Forsythia ×intermedia</jats:italic> `Lynwood', and <jats:italic>F. suspensa.</jats:italic> Taxon hardiness was based on the mean temperature at which low temperature exotherms (LTEs) occurred during thermal analysis. Ethanol-extracted soluble sugars were quantified with anthrone, and starch was enzymatically digested and quantified with Trinder reagent. Qualitative changes in sugar content were determined with high-performance liquid chromatography and co-chromatography of authentic standards. Quantitative and qualitative changes in sugar content, similar for the three taxa, were observed in conjunction with fluctuations in flower bud hardiness, although neither TSS nor starch were correlated with mean LTE temperature. TSS was higher in acclimated than nonacclimated buds. However, after deacclimation began, sugars continued to increase with mean LTE temperature. Buds lacked starch except for a brief period during deacclimation. Galactose, stachyose, raffinose, and an unidentified carbohydrate were positively correlated with hardiness <jats:italic>(P</jats:italic> = 0.005, 0.001, 0.005, and 0.001, respectively).</jats:p>

Relationship of Seasonal Changes in Carbohydrates and Cold Hardiness in Canes and Buds of Three Red Raspberry Cultivars

“…Hence, despite their small relative concentrations, raffinose and stachyose may have a decisive role also in freezing tolerance. Correlation of raffinose family oligosaccharides to cold hardiness has been reported previously (Ashworth et al, 1993;Flinn and Ashworth, 1995;Hamman et al, 1996;Imanishi et al 1998;Stushnoff et al, 1993). Although correlation coefficients between cold hardiness and carbohydrates were highly significant, the correlation analysis as such does not prove a causal relationship between these variables.…”

“…An increase in starch content coincides with budbreak in redosier dogwood (Ashworth et al, 1993) and in Forsythia sp. (Flinn and Ashworth, 1995). Accumulation of total soluble carbohydrates was caused mainly by an increase in sucrose.…”

“…Syme] (Stushnoff et al, 1993), redosier dogwood (Cornus sericea L.) (Ashworth et al, 1993), Forsythia species [F. ×intermedia Zabel, F. suspensa (Thunb.) Vahl] (Flinn and Ashworth, 1995), grape (Hamman et al, 1996) and Lonicera caerulea L. (Imanishi et al, 1998).…”

Mobilisation of nutrients and transport via the xylem sap in a shrub (Ligustrum ovalifolium) during spring growth: N and C compounds and interactions

“…Carbon was present primarily as stachyose, which often represented more than 50% of the speciated C. This sugar is characteristic of the Oleaceae family (Flinn and Ashworth, 1995) and is not found in other deciduous or evergreen trees (Hoch et al, 2003). Stachyose, a tetra-holoside, is a soluble molecule with high energy content.…”

Cold storage to overcome dormancy affects the carbohydrate status and photosynthetic capacity of Rhododendron simsii

“…Further, raffinose and stachyose were formed in response to cold, this mainly in flower buds. These oligosaccharides also increased in flower buds of Forsythia (Flinn & Ashworth ) during cold acclimation. As raffinose and stachyose interact with membranes, they can increase membrane stability (Hincha et al .…”