Changes in the starch and protein reserves ofAraucaria araucana(Mol.) Koch embryo and megagametophyte tissue during the first 90ensp;h after the start of imbibition have been measured by colorimetric and by chromatographic methods. The starch content (about 30) of the embryo decreases rapidly until radicle protrusionndash;germination (40ensp;h) and remains relatively constant (at about 9) after that. Starch content of the megagametophyte decreases slowly throughout the 90ensp;h. Amylase activity and soluble carbohydrate content of the embryo peak rapidly at 20ensp;h, decline rapidly until germination, and increase slowly thereafter. Total amylase activity of the megagametophyte does not change markedly. Total soluble-protein content of the embryo decreases during the first 20ensp;h and increases thereafter. The embryo protein bodies also disappear during the first 20ensp;h. The hypocotyl enlarges to a bulbous shape and may serve as a secondary protected reserve.
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