Germination Inhibitors in Fruit Extracts of Red Beet (Beta vulgariscv.rubra

Abstract

Germination inhibitors in methanol and water extracts of red beet fruits (Beta vulgaris cv. rubra L.) have been studied using lettuce and red beet seed germination as bioassays. The methanol extracts contained substances which inhibited lettuce seed germination, but had no effect on the germination of red beet seeds. Germination of both lettuce seeds and of water-leached or sulphuric acid-treated red beet seed balls were inhibited by the water extracts. The concentrations of ammonia, ferulic acid, and oxalate in the water extracts were much lower than required for inhibition of red beet seed germination. The water extracts contained, however, large amounts of inorganic ions, and the results clearly demonstrated that the inhibitory effect of the water extracts on red beet seed germination was mainly due to the content of such inorganic ions.