Comparative analysis of petal epidermal wax composition and loss-water resistance in five cut lily cultivars (Lilium spp)

Abstract

Plant epidermal wax is the primary barrier to non-stomatal transpiration, and of great significance for plants to resist loss-water stress. In this study, the crystal morphology and chemical composition of the petal epidermal wax of five cut lily cultivars were studied. The waxy crystal morphology of five cultivars was ellipsoidal. Petal epidermal wax was mainly composed of very long-chain fatty acids and their derivatives. The carbon chain lengths of straight-chain alkanes were in the range of C19–C34, with the main ones being C19, C25, and C34. The content of C25 straight-chain alkanes in cultivar ‘Manissa’ was as high as 65.9%. Further research on the water permeability of each material showed that ‘Manissa’ had the highest total wax content and low water permeability, while cultivar ‘Siberia’ had the lowest wax content and the highest water permeability. Determination of relative water content, relative electrical conductivity, and malondialdehyde content indicated that loss-water stress caused the least damage to cultivars ‘Manissa’ and ‘Ruby’, while ‘Siberia’ suffered the most serious injury. These results demonstrated that lily cut flower petals with higher epidermal wax content, had stronger loss-water stress tolerance, and there was a positive correlation between the two. These findings provide new options for genetic breeding to improve the loss-water stress tolerance of cut flowers.