Sunlight Differentially Affects the Fruit Skin, Flesh, and Core Coloration of the Type 2 Red-fleshed Apple ‘Kurenainoyume’: Optimization of Fruit Bagging Treatment

Abstract

We investigated the effect of fruit bagging treatment using three kinds of paper bags differing in light permeability on the red coloration of skin, flesh, and core in type 2 red-fleshed 'Kurenainoyume' apples by comparison with type 1 'Goshogawara' apples. Skin coloration of both 'Goshogawara' and 'Kurenainoyume' was affected by light and the effect was more marked in 'Kurenainoyume' than 'Goshogawara'. In contrast, the effect of fruit bagging treatment on the red coloration of the core was limited in 'Goshogawara', while core coloration was not observed in 'Kurenainoyume' type 2 apples. Flesh coloration was observed even under dark conditions in both cultivars, and the light tended to enhance the flesh coloration to some extent in both cultivars. Since fruit bagging treatment is a prerequisite for 'Kurenainoyume' to prevent cork spot-like physiological disorder (CSPD) in the skin, we optimized the fruit bagging treatment conditions using a light impermeable double-layered paper bag (2-layer bag), considering both prevention of CSPD and the red coloration of 'Kurenainoyume' skin and flesh. Bag-removal at 25, 35, and 45 days before harvest (DBH), resulted in good skin and flesh coloration without CSPD incidence. Moreover, there was no significant difference in fresh weight, soluble solid, or malic acid contents compared with the non-bagging control. Therefore, we recommend bag-removal from 25 to 45 DBH for 'Kurenainoyume' as a practical cultivation technique.

Effects of Low Temperature, Shading, Defoliation, and Crop Load on the Flesh Coloration of the Type 2 Red-fleshed Apple ‘Kurenainoyume’

“…In grapes, the associated MYB/bHLH/WD40 complex was decreased under low light intensity and dark conditions, which in turn resulted in a decrease in anthocyanin content through down-regulation of structural genes (Azuma et al, 2012). Red coloration of a type 2 'Kurenainoyume' apple skin was drastically induced upon exposure to light conditions after paper bag removal (Matsumoto et al, 2018b). This result is in line with the previous reports that skin coloration is controlled by the MdMYB1/A/10 gene (Ban et al, 2007;Espley et al, 2007;Takos et al, 2006).…”

“…In contrast, detailed environmental cues for flesh coloration are not satisfactory, let alone their elucidation at the molecular level. However, the effects of sunlight on flesh coloration were not as large as expected (Matsumoto et al, 2018b). Therefore, in this study, we first investigated the effect of temperature on flesh coloration of 'Kurenainoyume' apple fruit.…”

“…However, it is well known that the fruit bagging treatment affects light conditions and, in turn, the red coloration of the apple skin, but little is known about its effect on flesh coloration. Hence, we investigated the effects of pre-harvest fruit bagging treatment on the red coloration of 'Kurenainoyume' apple skin, core, and flesh (Matsumoto et al, 2018b). We observed that light affected the red coloration of 'Kurenainoyume' apple skin, but did not have a marked positive effect on the coloration of the flesh (Matsumoto et al, 2018b).…”

“…Hence, we investigated the effects of pre-harvest fruit bagging treatment on the red coloration of 'Kurenainoyume' apple skin, core, and flesh (Matsumoto et al, 2018b). We observed that light affected the red coloration of 'Kurenainoyume' apple skin, but did not have a marked positive effect on the coloration of the flesh (Matsumoto et al, 2018b). In contrast, it is known that several factors including temperature, plant hormones, and sugar content, other than light conditions, are involved in anthocyanin biosynthesis (Roubelakis- Angelakis and Kliewer, 1986;Xie et al, 2012).…”

Productivity and quality of bagging fruit of hybrid tomatoes

“…Among insects control alternatives, the tomato bunch bagging is being studied because it promotes a physical barrier that aims for insect and pathogens damage reduction and conservation of high fruits quality (COSTA et al, 2017). Bagging is a common practice in fruit growing especially on crops such as mango (NAGAHARSHITHA; VIMALA; HALDANKAR, 2014; RATHORE; PAL, 2016; REHMAN et al, 2015), apple (MATSUMOTO et al, 2018;FENG et al, 2014), guava (NANDI et al, 2016 and peach (ZHANG et al, 2015;GUIXIANG et al, 2017).…”