Variation in Thiocyanate Content of Radish Plants During Ontogeny1

Abstract

Abstract Large differences occurred in thiocyanate (SCN − ) content in roots and various tissues of the top of radish ( Raphanus sativus L.) during ontogeny. In the root of ‘Burpee White’ and ‘Champion’, a decreasing content in SCN − occurred during rosette (vegetative) growth; thereafter, only small changes in SCN − content of roots were observed to flowering. In the foliage of both cultivars, a decreasing content in SCN − during growth of the rosette, as in the root, preceded large increases during reproductive growth. The highest amounts of SCN − in the foliage were found at early bolting. The SCN − content in vegetative and reproductive tissues decreased with age. Throughout ontogeny, the occurrence of large amounts of SCN − in young photosynthetic tissues, particularly in the emerging leaves, indicated that such tissues are probably major sites of synthesis or storage of SCN − precursors. Differences in the SCN − content of foliage and marketable roots of 14 radish cultivars were indicative of genetic control of thiocyanates in radishes.