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CBN-V Video
Archives - S7-03
Evaluation of Four Cassava Clones Introduced from CIAT-Colombia,
Reproduced through in vitro Tissue Culture
Alfaro J.C.1 and Y.
Morales2
1. Carrera de Agronomía, U.A.G.R.M.
,Casilla 702, Santa Cruz, Bolivia
2. Fundación Amigos de la Naturaleza, Casilla 2241. Santa Cruz,
Bolivia ymorales@fan-bo.org
This study was carried out at the Universidad Autónoma Gabriel René
Moreno, Santa Cruz, Bolivia. The plant material used corresponds to
four cassava clones brought from the Banco de Germoplasma at CIAT,
Colombia and one local control cultivar. The study was done with a
random block design with five treatments and four repetitions. The
laboratory procedures involved preparation of culture media,
selection of laboratory material and micropropagation. Cassava
plantlets were acclimated and later taken to the field for the
necessary evaluations, being planted in the field in Jan 1998 and
harvested in Jan 1999. The following data were registered: height of
the plant, diameter of the stem, height of the first ramification,
evaluation and diagnosis of diseases, evaluation and diagnosis of
pests, harvested roots, yield of cassava and starch content. The
characteristics showed significant differences in the variance
analysis. They were submitted to multiple comparisons of their
mediums through the Tukey statistical analysis. The four clones
being studied showed a greater degree of direct response to
climactic variations, with regard to the development of the culture;
however the Rama Negra control variety presents more natural
rusticity toward adverse conditions, showing a uniform development
curve throughout its cycle. The Rama Negra control and the CM1335-4
and CM1585-13 clones present heights of about 160 cm, whereas the SG
104-284 and CG1139-2 clones present much greater heights,
fluctuating between 200 and 220 cm. The Rama Negra control and the
CM 1585-13 clone present a relatively low first ramification height
of 42 and 68 cm, respectively, that hinders manual weed control,
whereas the SG 104-284, CM 1335-4, CG 1139-2 clones do not have that
problem because this value is over 75 cm. With regard to diagnosed
diseases (Cercospora henningsii and Uromyces manihotis),
the clones and the Rama Negra control are in the ‘resistant’
category, except CG 1139-2 that is in the ‘intermediate’ category
with regard to mildew (Uromyces manihotis), but all are
usable commercially. CM 1335-4 (16.1 t/ha) and SG 104-284 (13.4
t/ha) clones show a much higher commercial yield than the Rama Negra
control (8.7 t/ha), although the latter has a value close to that of
the CG 1139-2 (9.0 t/ha) and CM 1585-13 (7.9 t/ha). The CG 1139-2
clone, with a slightly higher commercial production than the
control, can be used as an alternative in commercial production.
2007©
Donald Danforth Plant Science Center All rights reserved.
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