Resumen

CASTILLO, ROSARIO DEL P et al. CLASSIFICATION OF GENOTYPES OF EUCALYPTUS GLOBULUS UNDER COLD CONDITIONS USING THEIR FREE AMINO ACIDS CONTENT ON LEAVES AND REGULARIZED DISCRIMINANT ANALYSIS (RDA). J. Chil. Chem. Soc. [online]. 2010, vol.55, n.1, pp. 11-18. ISSN 0717-9707.  doi: 10.4067/S0717-97072010000100005.

Eucalyptus globulus is an important forestry species for wood and pulp industry; however, its low cold resistance is a serious disadvantage. In this work, chemometric techniques were applied onthe leaves'free amino acid content of different E. globulus genotypes in orderto select cold tolerant genotypes. Pattern recognition methods based on regularized discriminant analysis (RDA) were used to classify the genotypes by cold resistance using samples' foliar damages as reference of cold resistance. Correlation between the amino acids content and cold resistance of genotypes was determined from a partial least squares (PLS) model. RDA models showed an excellent classification of genotypes (100% of correctly assigned genotypes in external validation), especially when RDA  was reduced to quadratic discriminant analysis (QDA). Arg, Tyr and Ala, showed the highest correlations with the foliar damage in the PLS model and they could be responsible to improve cold resistance to the studied genotypes.

Palabras clave : regularized discriminant analysis (RDA); amino acids; cold resistance; Eucalyptus globulus.