The aerial surfaces of plants are covered with a wax layer that serves the essential functions of limiting non-stomatal water loss and acting as protective barrier against environmental stresses. We selected two broccoli lines, bloomed (MC91) and bloomless (MC117), and analyzed their phenotypes related to cuticular wax accumulation. The total wax amount was 1.93-fold higher in MC91 leaves compared to MCI 17 leaves. All of the studied cuticular wax compounds were 1.07-3.79-fold higher in MC91 plants compared to MCI 17 plants except for the C-31 alkane. The wax compositions did not essentially different between the two broccoli lines, but some compounds were found at significantly higher levels in MC91 plants compared to MCI 17 plants, mainly reflecting differences in C-29 alkanes, C-29 secondary alcohols and C-29 ketones. To investigate gene regulation by bloom phenotype, we analyzed the mRNA expression patterns of various cuticular wax biosynthetic genes. Our results revealed that LACS1, KCS1, KCR1, ECR, CER3 and IWAII1 were expressed more in MC91 plants compared to MCI 17 plants at both 3 and 10 weeks. The expression levels of the studied cuticular wax biosynthetic genes were significantly induced by drought stress, which is known to induce cuticular wax deposition. Together, these results show that the cuticular wax accumulation of broccoli is regulated by cuticular wax biosynthetic gene expression and can be affected by environmental signals. (C) 2015 Elsevier Ltd. All rights reserved.