Effects of Night-Heating of Fruit on Cell Size Regulation and Sucrose Accumulation in the Outer Portion of Watermelon (Citrullus Lanatus Matsum. Et Nakai)

Effects of Heating Bearing Shoot near Fruit on Cell Size, Sucrose Metabolizing Enzymes and Sugar Accumulation in Watermelon Fruit

“…10, C) is significantly smaller than that of the control fruit is contradictory to the results that nighttime heating of fruit early in development (Fig. 10, A) accelerated cell enlargement of melons (Kano, 2006) and watermelons (Ikeshita et al, 2010;Kano et al, 2008a). Cell size of the heated fruit for 20 days from 5 DAA is the same as that of the control fruit (Fig.…”

“…These reports point out that fruit maturation is accompanied by an increase in SPS activity, resulting in an increase in fruit sucrose content. Increased sucrose content of melon (Kano, 2006) and watermelon (Kano et al, 2008a) fruit by night-time heating of fruit early in development, and the high sucrose content in netted melon fruit grown at higher night-time temperatures (Kano and Fukuoka, 2006;Suzuki and Masuda, 1961;Suzuki et al, 1986Suzuki et al, , 1993, are considered to be the result of higher temperatures accelerating fruit and cell development. Cells of melon fruit heated at night during the early stage of fruit development enlarge and mature, which induces an earlier increase in SPS activity, which in turn, promotes sucrose accumulation, leading to a high fruit sucrose .…”

“…A strip, approximately 20 mm long, was removed from the disk with 10 mm straddling the line of the maximum diameter across each disk (Kano et al, 2008a). From the central portion (L2, L3, and R3, R2) of the left-hand and right-hand mesocarp of the strip, each rectangular parallelepiped (designated as a segment) 10 mm wide was sampled across the diameter of the disk.…”

“…Seven 10 μm-thick sections were prepared from these paraffin blocks, and the clearest section from each segment of each treatment was examined under a microscope (hereafter, referred to as segments L1-5 or R1-5). The maximum diameter of individual cells on the maximum transverse diameter of the segments was measured (Kano et al, 2008a).…”