Dissertação
Estudo da germinação e do efeito de Trichoderma spp. no crescimento de Gochnatia polymorpha (LESS.) Cabrera
Fecha
2012-02-24Registro en:
MACHADO, Daniele Franco Martins. Study of the germination and effect of Trichoderma spp. in the growth of Gochnatia polymorpha (LESS.) Cabrera. 2012. 101 f. Dissertação (Mestrado em Ciências Biológicas) - Universidade Federal de Santa Maria, Santa Maria, 2012.
Autor
Machado, Daniele Franco Martins
Institución
Resumen
The production and cultivation of native tree seedlings have difficulties that can be
attended to through the knowledge of the environmental factors and microorganisms affecting
seed germination, as well as the interaction between forest species and the Trichoderma,
which is a genus of fungi used in plant pathogens biological control and promotion of plant
growth. This study aimed to investigate the germination of Gochnatia polymorpha
(Less.)Cabrera, identifying the fungi associated with diaspores and evaluate the effect of
Trichoderma spp. in promoting germination and plant growth. In the study of seed
germination, the seeds have been subjected to temperatures of 15°, 20°, 25° and 30° C with a
photoperiod of 16 hours and continuous darkness. In another experiment the effect of sodium
hypochlorite (NaClO) has been evaluated on seed germination and contamination of the seeds
with and without Papus at concentrations of 0, 1, 2, 3 and 4%. Identification of fungi present
in the diaspores has been performed by the methods of filter paper and plating on BDA
culture medium. In the study of the interaction between G. polymorpha and Trichoderma spp.
TSM1 and TSM2 isolates of Trichoderma viride, 2B2 and 2B22 of Trichoderma harzianum
and two commercial products, Agrotrich® and Trichodermil®, have been analyzed in the
contamination of and germination of the seeds, using the cellophane in vitro technique .The
antagonism of these isolates to four fungi of the genera Bipolaris, Alternaria, Cladosporium
and Phoma, previously isolated from diaspores, has been evaluated by the technique of direct
confrontation. The ex vitro interaction experiments have been conducted in a greenhouse with
autoclaved and not autoclaved substrates. It has been concluded that the seeds germinated
both in the presence and absence of light and temperatures of 15° and 20° C have been the
most appropriate. The tested concentrations of NaClO did not interfere with seed germination,
but in diaspores with papus the lowest contamination rates have been in the concentrations of
0% and 4%; yet in the diaspores without papus, the lowest rates have been in the
concentrations of 3, 4 and 0%. In the diaspores the fungi genera Bipolaris, Alternaria,
Cladosporium, Phoma, Aspergillus and Epicoccum have been identified. By the technique of
in vitro cellophane, all tested isolates of Trichoderma spp. have been effective in controlling
the contamination of the seeds, but it has been not possible to assess the effect of
Trichoderma spp. in seed germination. In direct confrontation technique, the 2B22 isolate and
the product Agrotrich ® have been the most effective. In both autoclaved and not autoclaved
substrates, the tested isolates did not interfere in seedling emergence, but the isolates of 2B2
and 2B22 of T. harzianum promoted the vegetative growth of G. polymorpha.