Dissertação em PDF - departamento de engenharia florestal - ufpr ...

ABSTRACT
Jatropha curcas is a forest specie that belongs to Euphorbiaceae family and is popularly
known as physic nut. Despite having high potential for biodiesel production, there is little
information and studies about the type, including the potential for vegetative propagation. To
this end, the aim of the study were the establishment in vitro under aseptic conditions of
different explants (epicotyls, hypocotyls, rootlets and cotyledons) of Jatropha curcas in
culture medium for multiplication from seeds of five provenances germinated in vitro. At the
first experiment, the seeds were germinated in culture medium Murashige and Skoog (MS)
with half strength of nutrients and without addition of sucrose, which were evaluated
disinfestation and germination of seeds from each origin. This experiment was conducted in
completely randomized design. After germination, the parts of each seedling were
transferred to complete culture medium Murashige and Skoog (MS) with different sources
and concentrations of growth regulators (benzylaminopurine, kinetin, thidiazuron, adenine
sulfate and indol butiric acid), interconnected, being this the second experiment, where were
evaluated contamination and oxidation of explants as well as qualitative and quantitative
parameters, such as bud and callus induction, color of buds and callus, callus texture, size
and number of buds and fresh and dry weight. This experiment was conducted in completely
randomized design with factorial arrangement. In the first experiment, the disinfection was
effective in only two of the five origins that were studied, and the contamination was mainly
by fungi and bacteria also, with a percentage of the origins of contamination ranging from 0
to 85%; germination happens in two of five origins, and the percentages of germination
ranged from 0 to 99,17%. In the second experiment, could be verified that both oxidation and
contamination of the explants happened in the seventh day of cultivation, with statistical
difference between the origins, combinations of growth regulators and explant sources for
both evaluations. The percentage of explants that induced buds and callus varied
significantly for origins, combinations of growth regulators and sources of explants. The color
of buds ranged from green to yellow, the color of callus ranged from cream, green and
brown, and the texture of callus ranged from compact and friable, all statistically different for
origins, combinations of growth regulators and sources of explant. As to quantitative
analysis, the number of buds that showed the best results, in general, happened for the
origin Santa Vitoria – MG, to the combination of growth regulators composed by MS medium
with addition of 27.8 µM of BAP and 0.5 µMof IBA, and for cotyledonary explants, with an
average of formation of shoots per explant of 5.02, 10.92 and 7, respectively. As for the size
of the shoots, this ranged from small seedlings (less than 0.1 cm), medium (between 0.1 and
1 cm) and large (greater than 1 cm), in which the majority of the shoots had small size. For
the variables fresh weight and dry weight, there was statistical difference for origins,
combinations of growth regulators and sources of explant, being the results, in general,
presented for the origin Janaúba – MG, for the combination of growth regulators compound
by MS medium supplemented with 27.8 µM of BAP and 0.5 µM of IBA, and for hypocotyls
explants type.
Keywords: Jatropha curcas; micropropagation; tissue culture.
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