You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
The Level and Distribution of Phenolic Plant Growth Inhibitors in Yam Tubers during Dormancy
C. R. Ireland and H. C. Passam
The New Phytologist
Vol. 97, No. 2 (Jun., 1984), pp. 233-242
Stable URL: http://www.jstor.org/stable/2432303
Page Count: 10
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
In this study a possible role for batatasin-type phenolic growth inhibitors in the control of dormancy and, therefore, the storage life of tubers of Dioscorea alata and D. esculenta, two economically important food yams, was investigated. After extraction, the level of endogenous growth inhibitory phenolics was estimated by a wheat coleoptile growth test and batatasins specifically determined by fluorescence spectroscopy and gas-liquid chromatography. There was a gradual decrease in growth inhibitory phenolics in tubers of both species during dormancy and in D. alata this closely paralleled a decrease in batatasin content. It was found that batatasin-type growth inhibitory phenolics accumulated rapidly in developing tubers just prior to the onset of dormancy and were assymetrically distributed, being concentrated in the proximal (head) region and in the peripheral zone just beneath the periderm. Gibberellin A3 treatment produced a promotion of the dormant period and a correlative rise in the growth inhibitory phenolic level. Effects of maleic hydrazide and ethylene chlorohydrin are also reported. The results are discussed in terms of the mechanism of dormancy control in these tubers and it is concluded that endogenous batatasin-type phenolics are involved in this.
The New Phytologist © 1984 New Phytologist Trust