Micropropagación clonal in vitro en Eucalyptus grandis y E. urophylla

THE EUCALYPTUS TREE (E. UROPHYLLA AND E. GRANDIS) IS AN IMPORTANT RESOURCE WHICH PROVIDES CELLULOSE AND HEMICELLULOSE USED IN PAPER MANUFACTURING IN VARIOUS PARTS OF THE WORLD, AND PARTICULARLY IN SOUTHEASTERN MEXICO. SEVERAL BIOTECHNOLOGICAL ADVANCES HAVE BEEN DEVELOPED TO SOLVE THE DIFFICULTIES RESULTING FROM GENETIC VARIABILITY IN SEED PROPAGATION PRESENTED BY THE EUCALYPTUS SPECIES. THIS REQUIRES THE STUDY OF DIVERSE STRATEGIES OF MICROPROPAGATION WHICH PERMIT THE OBTAINMENT AND MULTIPLICATION OF EUCALYPTUS CLONES. THUS, THE OBJECTIVE OF THIS STUDY WAS TO ESTABLISH THE TECHNOLOGY FOR THE IN VITRO CLONAL MICROPROPAGATION OF SELECTED GENOTYPES, FOR THE PURPOSE OF OBTAINING HIGH QUALITY PLANTS FOR PLANTATIONS OR CLONAL ORCHARDS IN SOUTHEASTERN MEXICO. FOR THE ESTABLISHMENT OF THE EXPLANTS TO IN VITRO CONDITIONS, THE DISINFESTATION TIMES OF THE EXPLANTS WERE EVALUATED, EMPLOYING A COMBINATION OF THREE LEVELS OF DISINFESTATIONS WITH ANTIBIOTIC (TERRAMYCIN 40 MG/100 ML) AND WITH FUNGICIDE (CUPRIMYCIN 150 MG/100 ML) AT 0, 10 AND 30 MINUTES, THUS OBTAINING UP TO 90% OF THE CULTURES FREE OF CONTAMINATION. IN ADDITION, AN EVALUATION WAS MADE OF THE MULTIPLICATION OF SHOOTS, CALLUS FORMATION AND ROOTING FOR BOTH SPECIES, COMBINING THREE LEVELS OF BENZYLADENINE (0.0, 1.0 AND 3.0 MG L-1) AND OF ACETIC NAPHTHALENE ACID (0.0, 1.0 AND 3.0 MG/L-1) IN A GAMBORG B5 CULTURE MEDIUM. AS MANY AS 9 SHOOTS PER CULTIVATED EXPLANT WERE OBTAINED, AND AN AVERAGE OF 5.5 ROOTS PER EXPLANT, COMBINING 3 MG L-1 OF BENZYLADENINE AND 1.0 AND 3.0 MG L-1 OF ACETIC NAPHTHALENE ACID. THE PROTOCOLS WERE ESTABLISHED FOR THE ACCLIMATIZATION OF THE PLANTS.