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Effects of reciprocal stem grafts on cyanide translocation in cassava

Published online by Cambridge University Press:  27 March 2009

M. Makame ,
M. O. Akoroda  and
S. K. Hahn
M. Makame
Affiliation:
International Institute of Tropical Agriculture, P.M.B. 5320, Ibadan, Nigeria
M. O. Akoroda
Affiliation:
International Institute of Tropical Agriculture, P.M.B. 5320, Ibadan, Nigeria
S. K. Hahn
Affiliation:
International Institute of Tropical Agriculture, P.M.B. 5320, Ibadan, Nigeria
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Extract

Cassava (Manihot esculenta Crantz) is a carbohydrate staple and cash crop for about 800 million people in the tropics. As food, its use is influenced by its content of potentially toxic cyanogenic glycosides that release hydrocyanic acid when enzymatically hydrolysed (Conn, 1969). Cyanide plays important role in the protection of cassava plants from attacks by animals and insect pests. The glycosides are synthesized mainly in leaves and translocated to all parts of the cassava plant (Bediako, Tapper & Pritchard, 1981). De Bruijn (1973) noted more than a 100% increase in the HCN content of stem bark above the incision after ringing, especially during the first 2 days, and a continued increase for at least 2 months. However, when leaves were removed, no such increase was observed. De Bruijn (1973) observed that younger plants showed a greater increase (165%) than older plants (65%). Leaf HCN did not increase after ringing, whereas root HCN decreased by about 20% in 2 weeks. The literature on cyanogenic glycoside translocation is relatively recent and limited. Consequently, the exploitation of the supposed direct relationship between leaf HCN and root HCN in the selection of low HCN clones in cassava breeding programmes needs to be carefully assessed. The assessment is complicated because the methods used by different workers for the determination of HCN vary in their efficiency. Thus, Cooke, Howland & Hahn (1978) found no correlation (r2 = 0·13) between leaf HCN and root HCN among 108 clones, yet over 88000 genotypes have been screened by analysis of leaf HCN, and leaf analysis has been used routinely in cassava improvement for 9 years (Hahn, 1983). Hahn also reported the range of HCN concentration within each leaf-picrate class (1 = 80, 2 = 80−200, 3 = 200 mg/100g fresh weight) but the ranges within each of these classes were too wide to enable effective selection for low HCN clones.

Type
Short Notes
Information
The Journal of Agricultural Science , Volume 109 , Issue 3 , December 1987 , pp. 605 - 608
Copyright
Copyright © Cambridge University Press 1987

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References

Bediako, M. K. B., Tapper, B. A. & Pritchard, G. G. (1981). Metabolism, synthetic site, and translocation of cyanogenic glycosides in cassava. In Tropical Root Crops: Research strategies for the 1980s (ed. Terry, E. R., Oduro, K. A. and Caveness, F.), pp. 143–148. Ottawa, Canada: International Development Research Centre (IDRC - 163e).Google Scholar
Conn, E. E. (1969). Cyanogenic glycosides. Journal of Agricultural and Food Chemistry 17, 519–526.CrossRefGoogle Scholar
Cooke, R. D. & Coursey, D. G. (1981). Cassava: a major cyanide containing food crop. In Cyanide in Biology (ed. Vennesland, B., Conn, E. E., Knowles, C. J., Westley, J. and Wissing, F.), pp. 53–111. London: Academic Press.Google Scholar
Cooke, R. D. & De La Cruz, E. M. (1982). The changes in cyanide content of cassava (Manihot esculenta Crantz) tissues during plant development. Journal of the Science of Food and Agriculture 33, 269–275.Google Scholar
Cooke, R. D., Howland, A. K. & Hahn, S. K. (1978). Screening cassava for low cyanide using an enzymatic assay. Experimental Agriculture 14, 367–372.Google Scholar
Dahniya, M. T. (1979). Defoliation and grafting studies of cassava (Manihot esculenta Crantz) and sweet potato (Impomoea batatas L.). Ph.D. thesis, University of Ibadan, Nigeria.Google Scholar
De Bruijn, G. H. (1973). The cyanogenic character of cassava (Manihot esculenta). In Chronic Cassava Toxicity (ed. Nestel, B. and Maclntyre, R.), pp. 43–48. Ottawa, Canada: International Development Research Centre.Google Scholar
De Bruijn, G. H. & Dharmaputra, T. S. (1974). The Mukibat System, a high yielding method of cassava production in Indonesia. Netherlands Journal of Agricultural Science 22, 89–100.Google Scholar
Hahn, S. K. (1983). Cassava research to overcome the constraints to production and use in Africa. In Cassava Toxicity and Thyroid: Research and Public Health Issues (ed. Delange, F. and Ahluwalia, R.), pp. 93–102. Ottawa, Canada: International Development Research Centre.Google Scholar
Naktey, F. (1981). Cyanogenesis in tropical feeds and foodstuffs. In Cyanide in Biology (ed. Vennesland, B., Conn, E. E., Knowles, C. J., Westley, J. and Wissing, F.) pp. 115–132. London: Academic Press.Google Scholar
Rao, P. V. & Hahn, S. K. (1984). An automated enzymic assay for determining the cyanide content of cassava (Manihot esculenta Crantz) and cassava products. Journal of the Science of Food and Agriculture 35, 426–436.Google Scholar
Sadik, S., Okereke, O. U. & Hahn, S. K. (1974). Screening for Acyanogenesis in Cassava. IITA Technical Bulletin No. 4, 4 pp. Ibadan, Nigeria: International Institute of Tropical Agriculture.Google Scholar