ALIPHATIC COMPONENTS OF THE EPICUTICULAR WAX OF DEVELOPING SASKATOON (AMELANCHIER ALNIFOLIA) FRUIT

The epicuticular wax of saskatoon fruit (Amelanchier alnifolia Nutt. c v. Smoky) was analyzed at four stages of maturity. Total wax per unit surface area varied during fruit development, with a net decline from the youngest to the most ripe stage. Surface wax ultrastructure, as re vealed by scanning electron microscopy, consisted of pinhead-like crys tals that decreased with maturity and platelike crystals that increase d with maturity. The major aliphatic compounds were alkanes (C-23 to C -29), long chain esters (C-36 to C-42), primary alcohols (C-20 to C-30 ), and a secondary alcohol (C-29). The esters were composed of primary alcohols (C-20 to C-28) and saturated fatty acids (C-16 to C-24). The most abundant wax components at all stages were nonacosan-10-ol and n onacosane.