Chemical Composition and Crystal Morphology of Epicuticular Wax in Mature Fruits of 35 Pear (Pyrus spp.) Cultivars

Abstract

An evaluation of fruit wax components will provide us with valuable information for pear breeding and enhancing fruit quality. Here, we dissected the epicuticular wax concentration, composition and structure of mature fruits from 35 pear cultivars belonging to five different species and hybrid interspecies. A total of 146 epicuticular wax compounds were detected, and the wax composition and concentration varied dramatically among species, with the highest level of 1.53 mg/cm2 in Pyrus communis and the lowest level of 0.62 mg/cm2 in Pyrus pyrifolia. Field emission scanning electron microscopy (FESEM) analysis showed amorphous structures of the epicuticular wax crystals of different pear cultivars. Cluster analysis revealed that the Pyrus bretschneideri cultivars were grouped much closer to Pyrus pyrifolia and Pyrus ussuriensis, and the Pyrus sinkiangensis cultivars were clustered into a distant group. Based on the principal component analysis (PCA), the cultivars could be divided into three groups and five groups according to seven main classes of epicuticular wax compounds and 146 wax compounds, respectively.

Insights Into Olive Fruit Surface Functions: A Comparison of Cuticular Composition, Water Permeability, and Surface Topography in Nine Cultivars During Maturation

“…An inverse relationship between triterpenoid acids and olive fly egg deposition has been reported elsewhere (Kombargi et al, 1998). Triterpenoids also have reportedly an important role in the mechanical strength of fruit cuticles (Tsubaki et al, 2013; Wu et al, 2018), and have been shown to be related to weight loss and softening rates in blueberry (Moggia et al, 2016). In this work, however, no such relationship was observed between the incidence of olive fly infestation and triterpene content ( Table 4 , Table S1 ).…”

Developmental and Environmental Regulation of Cuticular Wax Biosynthesis in Fleshy Fruits

“…Apart from alkanes and triterpenoids, many fruits have high proportions of other components in their cuticles. A recent study indicated high levels of primary alcohols and tocopherols in the cuticular wax of some pear cultivars (Wu et al, 2017, 2018). Plum ( Prunus domestica ) and some apple cultivars show high proportion of secondary alcohols in fruit cuticle, while tomato cuticle contains significant amounts of polyunsaturated constituents, including alken-1-ols and alkenes (Kosma et al, 2010).…”

Network Analyses and Data Integration of Proteomics and Metabolomics From Leaves of Two Contrasting Varieties of Sugarcane in Response to Drought

“…lAAld can be oxidezed to the auxin indole-3-acetic acid (IAA) and is related to the tryptophan metabolim (Tsurusaki et al, 1997). Octadecanal is a lipid, found in the cuticular wax of maize (Perera and Nicolau, 2007) and epicular wax of pear fruits (Wu et al, 2018). All metabolites were negatively correlated with two chloroplastic proteins: translocase and a protease.…”