PATTERNS OF VARIATION AND GEOGRAPHIC DISTRIBUTION IN FOLIAR CHEMICAL PHENOTYPES OF Persea americana var. drymifolia

Abstract

Wild Persea americana var. drymifolia (creole avocado) is found in forests with a precarious conservation state. The foliar chemistry of creole avocados from the Germoplasm Bank of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias in Celaya, Guanajuato, one of the most representative banks for this avocado variety in México, was estudied. We sampled 291 trees belonging to 35 accessions from seven Mexican states. The foliar chemical profile was determined by gas chromatography coupled to a mass spectrometer. We found and quantified the concentration of 33 compounds, out of which 28 were identified. The most abundant compounds were estragole and caryophyllene, each representing over 10 % of the total concentration in the sample. The chemical variation of the trees was classified by a cluster analysis in which groups and sub-groups with 40 to 60 % of similarity were formed. The chemical subgroups containing most of the trees at 40 % of similarity were differentiated mainly by estragole, sabinene and β-cubebene. Estragole, caryophyllene, p-cimene β-phellandrene and chavicolmethyl- ether were the characteristic components in other sub-groups with 60 % of similarity. A greater variation was found between the states of México than within them, for most chemical compounds.