High-value application of cassava starch in root crop micropropagation for sustainable seed systems in developing countries
Despite the high cost of micropropagation, the use of tissue-cultured planting materials is now widely practiced in several crop production ventures in developing countries. One of the high-cost items in micropropagation is the agar as gelling agent of the culture medium, which is imported. This study examined the feasibility of using locally available cassava starch as a low-cost agar substitute in the micropropagation of purple yam and cassava. Starches from two cassava cultivars ('Lakan-1' and 'Rayong-5') were tested at different levels. Results showed normal growth and development of purple yam nodal cultures at all levels of starch used. However, at 8% starch, the medium was so soft that the nodal tissues were submerged, thereby causing a delay in shoot and root growth. Starch concentrations of 9% in both cultivars appeared to be optimal for yam, wherein culture responses were comparable to that of the usual 0.7% agar. However, for cassava, regardless of concentration, both starches were found to be unsuitable, because the cultures did not exhibit normal growth and development. Cost analysis of the use of 9% cassava starch revealed a more than 10-fold saving relative to the use of 0.7% agar.
Acedo, V.Z., Hinay, N.G., Binongo, M.M. and Antona, J.Q. (2017). High-value application of cassava starch in root crop micropropagation for sustainable seed systems in developing countries. Acta Hortic. 1179, 293-298
gelling agent, agar substitute, tissue culture, Manihot esculenta Crantz, Dioscorea alata L