Chemotaxonomic significance of leaf wax alkanes in the gramineae

Leaf wax alkanes were determined in several species of the grass family (Gramineae) and used as chemotaxonomic characters. Leaf wax alkanes were extracted with hexane and determined by GC-MS on a data set including 93 species belonging to five subfamilies: Bambusoideae, Pooideae, Arundinoideae, Chloridoideae and Panicoideae. The large data set on the Pooideae allowed consideration of the chemotaxonomic significance of leaf wax alkanes in the tribal classification of this family. The data obtained were statistically processed by using multivariate methods including cluster analysis, principal component analysis and discriminant analysis. The partitions provided by the statistical analyses presented many interesting systematic correlations with morphological data both at subfamilial and tribal level. The results of this study confirm the usefulness of leaf wax alkanes as chemotaxonomic markers.