The effect of soil drought on the composition of carbohydrates in yellow lupin seeds and triticale kernels

Carbohydrate analysis was made of yellow lupin seeds (cv. June) and tritica le kernels (cv. Dagro), produced by plants exposed to drought stress for 21 days after the initial flowering of the first node of lupin and initial ea ring of triticale. The seeds of all experimental variants were harvest at f ull maturity, dried and stored in linen bags at 18-20 degreesC. Soluble car bohydrates were extracted and analysed as described by Horbowicz and Obendo rf (1994). Gas chromatographic separation of carbohydrates showed that raffinose famil y oligosaccharides (RFO) were dominant in lupin seeds. The other carbohydra tes present were sucrose (10 %), cyclitols and galactosyl cyclitols (12-13 %). Soil drought resulted in higher levels of verbascose, but decreased the quantities of the other carbohydrates in lupine seeds. In triticale kernels, over 50 % of soluble sugars were composed of sucrose and maltose, while 17.7 % were raffinose and stachyose. In response to drou ght the content of mono- and oligosaccharides declined. The decrease of sol uble carbohydrates content in seeds of lupin and triticale kernels has no e ffect on the seed germination and vigour. It is assumed that the changes in the concentration of soluble sugars observed under drought may impair the storability of triticale kernels, but improve it for lupine seeds.