MICROORGANISMOS ASOCIADOS A LA SEMILLA DE TRES ESPECIES DE PINO Y TÉCNICAS DE DESINFECCIÓN

Abstract

The objectives of tbis study were the intem and extern contaminants identification on seed recollection, .and test severa! promoters and disinfectants of gennination on three pine species (Pinus michoacana Martínez., P pseudostrobus Lindl. and P. douglasiana Martínez.). The seeds were collected at Barranca de Cupatitzio Experimental Station, located on Micboacan state, Mexico. Por seed contaminant detection, there were carried out laboratory tests with the focus to obtain pure cultivations of microorganisms and identify them. Also were carried out severa! experiments, under a randomized desing, they were applied the disinfectants Hidrogen Peroxide and Sodium Hipoclorite. Finally a seed experiment with Pinus pseudostrobus was conducted to prove the efficiency on different inmersion times, using Hidrogen Peroxide as germination promoter.
The results showed the existence of endobiotic and epibiotic contaminants on the three pine species. Pinus michoacana was the specie with highest contamination and P. douglasiana was the less contaminated. The contaminant agents genus identified on the seeds were: Botrytis, Pesta/otia, Rhyzopus, Penicillum and Aspergillus: a bactery of Xanthomas genus was founded as contaminating material on Pinus michoacana and P. pseudostrobus seeds. It was comproved that Hidrogen Peroxide wasn't a good pine seed desinfectant, however with 40 and 60 minutes exposition times with Sodium Hipoclorite at 1 percent, reduced 8 and 15 percent microorganisms presence on the three pine species, respectively. The seed inmersion showed a 100 percent epibiotic contaminants control using Sodium Hipoclorite at 1 percent, applied with 4 and 6 minutes. The inmersion of P. pseodostrobus seed on Hidrogen Peroxide with 5, 10 and 20 minutes, increased the germination on 18.6, 15.9 and 12.6 percent, respectively.