OCCURRENCE OF SORBITOL (D-GLUCITOL) AND CERTAIN RELATED SUGARS IN GERMINATING SEEDS AND DEVELOPING SEEDLINGS OF MALUS

Abstract

The amounts of sorbitol (D-glucitol) and related sugars in Malus grown in daylight and dark were estimated by chromatographic means. Fructose was the largest single soluble carbohydrate fraction in the seed. Sorbitol was found in germinating apple seed, and in all organs of the developing seedling, including the root. Photosynthesizing cotyledons appeared to be a site of synthesis of sorbitol. The results show sorbitol to be a reserve form of carbohydrate in seeds and cotyledons of apple. Sucrose was the major translocate. The oligosaccharides melibiose, raffinose, and stachyose were present in germinating seeds. They seem to serve a storage role in the seed, for they quickly disappeared during germination and did not appear in the actively growing seedling either in light or dark. An unidentified oligosaccharide was present in germinating seeds in appreciable quantity.