Effect of Heating Fruit on Cell Size and Sugar Accumulation in Melon Fruit (Cucumis melo L.)

Abstract

<jats:p>To investigate the relationship between cell size and sugar accumulation, fruit of the melon was heated during the early stage of the growing period. The minimum air temperature in the heating apparatus was ≈10 °C higher than the ambient air temperature, and the weight of the heated fruit was greater than that of the control fruit. The number of rectangular parallelepiped (7-mm-long sample serially collected beginning at one end of the 10-mm-wide strip removed from the 10-mm-thick disk at the maximum transverse diameter of the fruit to the opposite end) with cells larger than 200 μm in the heated fruit at 17 days after anthesis (DAA, the end of heating treatment) was much larger that of the control fruit. The mean cell size in the heated fruit at 17 DAA was larger than that of the control fruit. Mean sucrose content of the heated fruit on 40 DAA was larger than the level in the control fruit. Higher fruit temperatures in melons covered with heating apparatus results in the predominance of larger cells and increased accumulation of sucrose in the fruit.</jats:p>

Regulation of phytochemicals in fruits and berries by environmental variation—Sugars and organic acids

“…However, it should be mentioned that the variation of experimental conditions between different investigations should be considered as well. For example, different varying trends of glucose in response to the elevation of temperature were reported in melon fruit of different cultivars (Kano, ; Matsumoto et al, ), which might be due to either genetic differences of the plants or the different temperature treatments applied on the plants in the two investigations. In the study by Matsumoto et al (), the shoots near melon fruits were heated at night to a minimum of 30°C from the fifth day after anthesis (DAA) until harvest, while in the other study (Kano, ), the heat treatment was applied directly to the fruit during the early stage of the growing period from 3 to 17 DAA.…”

“…For example, different varying trends of glucose in response to the elevation of temperature were reported in melon fruit of different cultivars (Kano, ; Matsumoto et al, ), which might be due to either genetic differences of the plants or the different temperature treatments applied on the plants in the two investigations. In the study by Matsumoto et al (), the shoots near melon fruits were heated at night to a minimum of 30°C from the fifth day after anthesis (DAA) until harvest, while in the other study (Kano, ), the heat treatment was applied directly to the fruit during the early stage of the growing period from 3 to 17 DAA. In the studies on black currants mentioned above, Woznicki et al () controlled the temperature at constant levels of 12°C, 18°C, and 24°C, respectively, for different treatment groups during the experiment period, whereas the black currant bushes were freely grown in open field and the temperature parameter were recorded for statistical analysis in the study by Zheng, Yang et al ().…”

“…In contrast, no impact of temperature was found on the concentrations of fructose and glucose in satsuma mandarins (Marsh, Richardson, & MacRae, ). In view of sucrose content, it increased in fruits of melon (Kano, ; Matsumoto, Kano, Madachi, & Aoki, ) and watermelon (Kano, Matsumoto, Aoki, & Madachi, ) but decreased in bilberries (Uleberg et al, ) and purple passion fruits (Utsunomiya, ) as temperature increased. The total sugar content showed a decreasing trend in strawberry (Davik et al, ; Wang & Camp, ) and watermelon (Fukuoka, Masuda, & Kanamori, ) as temperature increased, while it did not vary in apple (Yamada et al, ).…”

“…In view of sucrose content, it increased in fruits of melon (Kano, 2006;Matsumoto,Kano,Madachi,&Aoki,2012)andwatermelon (Kano,Matsumoto,Aoki,&Madachi,2012)butdecreasedinbilberries (Uleberg et al, 2012) and purple passion fruits (Utsunomiya, 1992)astemperatureincreased.Thetotalsugarcontentshoweda decreasing trend in strawberry (Davik et al, 2006;Wang & Camp, 2000) and watermelon (Fukuoka, Masuda, & Kanamori, 2009) as temperature increased, while it did not vary in apple (Yamada et al, 1994). Moreover, different responses of sugar concentrations in fruits of the same species but different cultivars have also been reported.…”

Local Temperature Control in Greenhouse Vegetable Production

“…On the other hand, the effectiveness of fruit heating was reported in the melon (Cucumis melo L.) and watermelon (Citurullus lanatus Matsum. et Nakai), in which sucrose accumulation was promoted in fruits (Kano, 2006;Kano et al, 2008Kano et al, , 2012Matsumoto et al, 2012). The effects of fruit heating may therefore differ among crops.…”