Fructan variations in tuberous roots of Viguiera discolor Baker (Asteraceae): the influence of phenology
1993
Isejima, E.M. | Figueiredo-Ribeiro, R. de C.L.
The content and composition of fructans in tuberous roots of Viguiera discolor Baker (Asteraceae), a perennial herbaceous species native to the Brazilian cerrado, are analysed according to season and in sequence from late dormancy (winter) to the beginning of the next dormant period (autumn). The general pattern of fructose found in decreasing concentrations of ethanol extracts is similar at each phenological phase. Hot water soluble fructans (high molecular mass inulin) are predominant throughout, particularly in the dormant period, and account for more than half the total fructan. Lower molecular mass components, especially free fructose, are present in higher amounts during the sprouting phase; this would indicate that hydrolysis occurs in association with the breaking of dormancy. The absence of oligosaccharides of intermediate size during the flowering/fruiting phase suggests they might be metabolized in the course of this process. The total concentration of fructans and the mean molecular mass of inulin remain high in spite of these variations.
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