Introduction:

A species' populations differ across its distribution due to selection pressure from the climate gradient.

Objective:

To describe the phytochemical variation among 14 tree provenances in an altitudinal gradient of Abies religiosa (Kunth) Schltdl. & Cham. to determine if there are associations of chemical profiles among populations, expressed under a single environment.

Materials and methods:

Seeds were collected from 165 trees from an altitudinal transect from 2 850 to 3 540 m in Cerro San Andrés, Municipio Libre de Hidalgo, Michoacán, Mexico. The plant was grown in a common garden trial; at 28 months, mature needles were collected per tree and analyzed by gas-mass chromatography. Data were analyzed with diversity indices, ANOVA and multivariate analysis (principal components, correspondences and cluster).

Results and discussion:

Thirty-two compounds were identified, most of them terpenes. The populations showed differences in presence/absence of terpenes and in their concentration; above 3 350 m, diversity was lower, but with higher concentration. Three altitude groups were found based on the chemical profile of the populations: low = 2 850 to 3 300 m and 3 400 m; moderate = 3 350, 3 450 and 3 500 m; and high = 3 540 m.

Conclusions:

The diversity and concentration of terpenes in A. religiosa varied depending on the altitude of populations. There are three chemical profiles that should be considered in the implementation of germplasm collection programs for reforestation and restoration.