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.