Evaluation of selected crop starches as an alternative cheap gelling agents for micropropagation of sweet potato (ipomoea batatas l.)
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Date
2009
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Sokoine university of Agriculture
Abstract
Experiments were conducted to investigate cheap gelling agents as substitutes to
agar in order to reduce the cost of micropropagation. Starches from cassava, sweet
potato, irish potato, wheat, sorghum, maize and rice were tested together with
0.08% (w/v) agar as control and sweet potato cv. Ukerewe was used as test plant.
Standard methods of determining physicochemical properties of the starch and
Tissue Culture (TC) were used. Nodal explant cultures were initiated in MS
(Murashige and Skoog, 1962) media supplemented with 3% sucrose and 0.5mg/I
Benzyl-Amino-Purine and gelled by seven starches each at concentrations: 12%,
15%, 18% and 21% (w/v). In vitro nodal explants were subcultured individually on
fresh media supplemented with 3% sucrose, 5 mg/1 gibberellins and solidified by
15% cassava, 11% sweet and irish potato starches. During culture initiation,
Cassava, sweet and irish potato starches outperformed the control in influencing the
number of leaves, nodes, height and fresh weight of in vitro shoots. Of the three
starch gelled media, sweet potato starch based media had the highest
micropropagation rate of 2058 in vitro nodal propagules in 84 days but it was lower
than that of the control which produced 3584 in vitro nodal propagules during the
same time. Highest media and propagule cost reduction of 44% and 67%
respectively was achieved by using sweet potato starch instead of agar. Therefore,
sweet potato starch has high potential to replace agar due to good plant growth and
low cost of the media.
Description
Dissertation
Keywords
Sweet potato evaluation