Changes in Ethanol Soluble Carbohydrates During the Development of Two Wheat Cultivars Subjected to Different Degrees of Water Stress

Abstract

The changes of ethanol soluble carbohydrates in leaves, stems, roots and ears of the wheat cultivars Yecora (semi-dwarf and early) and Generoso (taller and late) were followed during development in the field with and without irrigation. Sucrose concentration remained at low levels during the vegetative phase in all vegetative organs except in the roots of Yecora, but increased consistently after ear emergence. Reducing sugars were at low concentrations throughout leaf development, but increased towards maturation in the roots and, more dramatically, in the stems of the non-irrigated treatment. Sucrose levels remained relatively stable in the ears, whereas glucose and fructose fell during grain filling. Raffinose was detected at low levels only in the ears. Yecora accumulated more sucrose in the leaves and roots before heading as a response to temporary water stress. From correlations between the leaf water potential and the corresponding values of the examined sugars, as well as from the examination of the time courses in the two treatments, it was found that only sucrose accumulation was related on several occasions with increasing water stress. No systematic differences between the cultivars were found in the association of sugars with plant water status.