• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.211-215
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• 2011

This study aimed to determine optimum leaves per shoot in 'Campbell Early' grape through investigating changes of fruit quality after veraison 70~75 berries of first cluster and 35~40 berries of second cluster at 30 days after full bloom. Soluble solids content (SSC) increased dramatically during 28 days after veraison and afterwards it was stabilized. 15 leaves per shoot treatment showed fast increase of SSC from early veraison and reached to over 16.0oBx at 28 days after veraison. No considerable increase of SSC were occurred on either 5 or 0 leaves per shoot treatments after veraison. Titratable acidity (TA) was decreased continuously during 28 days of berry ripening in the all treatments. In 15 leaves per shoot treatment, TA decreased fast during first 7 days after veraison and continuously decreased to 0.5% by harvest time. While, 5 and 0 leaves per shoot treatments showed TA decrease slightly only at the early veraison. Hunter L and b values of 15 leaves per shoot treatment decreased fast during first 7 days of veraison, and gradually decreased by 14 days, whereas Hunter a value increased fast during the first 7 days from veraison. Total anthocyanin content in 15 leaves per shoot treatment increased fast from 7 days of veraison and the increase became slow after 28 days of veraison. Other treatments showed no significant difference from veraison to harvest time.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.298-303
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• 2005

This experiment was carried to investigate the optimum time and times of abscisic acid (ABA) treatment for the coloration in 'Kyoho' grapes. The L-phenylalanine ammonia-lyase (PAL) enzyme activities were showed highly in both ABA treatments at veraison and 10 days after veraison. However, PAL enzyme was slightly higher in ABA treatment at 10 days after veraison than in that at veraison. Anthocyanin content showed a tendency that were increased during fruit development after veraison in all treatments, and was the highest in ABA treatment at 10 days after veraison. Fructose and glucose as soluble sugars were detected by HPLC and showed little differences in all treatments. In times of ABA treatment, PAL activity showed a tendency that decreased after increased in all treatments. PAL activity in 2 times treatment of ABA was higher than other treatments. Also, anthocyanin content was highest in 2 times treatment of ABA, as 5 folds of control and folds of 1 time treatment of ABA. Both fructose and glucose contents in all ABA treatments was slightly higher than control.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.954-958
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• 2010

The study was conducted to investigate the relationship between berry set density per bearing shoot and fruit quality in 'Kyoho' grape. Fruit quality was evaluated by soluble solids content (SSC), titratable acidity (TA), skin color, and total anthocyanin content (TAC). There was a sharp increase in SSC of fruit juice from veraison initiation to 30 days after veraison. The SSC level increased with the lower berry set per bearing shoot. The rapid accumulation of SSC 4 weeks after veraison in the cluster of low berry set (10-20) was observed, while that of high berry set (40-50) showed delayed and low SSC accumulation which reached only $15.0^{\circ}Bx$ at harvest. TA of fruit juice in all treatments reduced rapidly from veraison initiation to 30 days after veraison, and then reduced gradually. TA in all treatments except 50 berries set reached to 0.4-0.6% which was optimal TA in 'Kyoho' at fruit harvest. During fruit maturing after veraison, fruit skin color changed from green to purple-black, L and b value decreased, and a value increased. TAC in 10 and 20 berries set was gradually increased to 2 weeks after veraison, sharply increased until 6 weeks after veraison, and then finally decreased, while TAC in content in 30, 40, and 50 berries set per annual shoot remained at low level. The results indicated that the number of berry set for good quality seemed to be 20 per bearing shoot in 'Kyoho' grape.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.295-303
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• 2021

We analyzed berry skin coloration, anthocyanin accumulation, and plant hormone contents in berry skins to determine the effect of night temperature at veraison on berry skin coloration in 'Kyoho' grapevines (Vitis labruscana L.). Vines were grown under 21, 24, and 27℃ at night for 20 days at veraison, from 40 to 60 days after full bloom (DAFB). Berry skin coloration of 'Kyoho' grapes was more suppressed in 27℃ treated vines, followed by that in 24℃ treated vines, than that in 21℃ treated vines. Cluster and berry weight and soluble solids content was lower in 24 and 27℃ treated vines than in 21℃ treated vines. Anthocyanin started to accumulate from 60 DAFB in berry skin of 21℃ treated vines, and malvidin and total anthocyanin content increased until 100 DAFB. The total and most of the individual anthocyanins decreased in 24 and 27℃ treated vines; however, peonidin did not decrease in 24℃ treated vines compared to that in 21℃ treated vines. Abscisic acid (ABA) peaked at veraison in berry skins of 21℃ treated vines and decreased thereafter until 100 DAFB. The increase in ABA content was inhibited in berry skins of 24 and 27℃ treated vines. Gibberellin (GA) content in berry skins decreased rapidly at veraison, with the decrease being slower under 27℃ than under 21℃. ABA/GA in berry skins of 21℃ treated vines peaked at 60 DAFB and decreased thereafter until 100 DAFB. However, ABA/GA decreased in berry skins of 24 and 27℃ treated vines, with reduced anthocyanin accumulation. Therefore, high night temperature (above 24℃) at veraison suppressed the berry skin coloration of 'Kyoho' grapes with changes in anthocyanin contents and composition due to the decrease in ABA/GA ratio and fruit soluble solids contents.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.213-221
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• 2018

We analyzed the skin coloration and anthocyanin composition of 'Kyoho' and 'Heukboseok' grape berries to determine the cause of poor coloring in 'Kyoho' berry skins under high temperature (HT) at veraison. Although the skin coloration inhibited in both 'Kyoho' and 'Heukboseok' berries under HT for 30 days from veraison, the total anthocyanin content in 'Heukboseok' berry skins increased to the level of control after the end of temperature treatment, but 'Kyoho' did not increase. Malvidin derivatives were most significantly reduced in 'Kyoho' berry skins, followed by those of delphinidin and petunidin. Among individual anthocyanins, diglucosides and acylated malvidin derivatives were most decreased in 'Kyoho' berry skins. Acylated and tri-hydroxylated anthocyanins were reduced more than those of non-acylated and dihydroxylated, respectively. All different types of anthocyanin components in 'Kyoho' berry skins decreased by HT, and they were similar to that of total anthocyanin. In 'Heukboseok' berry skins, accumulations of all different types of anthocyanins were inhibited by HT, and increased to the level of control after the end of the treatment. These results suggest that the poor coloration of 'Kyoho' under HT at veraison was not caused by the decrease of specific anthocyanins but because the whole anthocyanin biosynthesis was suppressed by HT.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.156-161
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• 2011

This experiment was performed in order to define the characteristic and quality of the fruits set on primary and secondary shoots in 'Heukgoosul' grape. The numbers of flower clusters per shoot were 1.1 and 0.6 in primary shoots and secondary shoots, respectively. The fruits of primary shoot showed 12.1 g of higher berry weight than 8.9 g of the fruits set on secondary shoots. Fructose and glucose contents were significantly higher in the fruits of secondary shoots during veraison, but the levels gradually decreased, reaching a similar level with those of primary shoot at the harvest stage. The acid content decreased rapidly from day 50 after full bloom in both primary and secondary shoots, but the rate of decrease slowed down from day 70 after full bloom in secondary shoots. Berries of secondary shoots showed rapid increase of skin coloration during veraison and reached a high degree of coloration within a short period when compared with those of primary shoots.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.495-509
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• 2016

Irrigation applications (IA) and increased bud load (BL) are fundamental practices that are used to achieve optimum yields in grape production, while maintaining fruit quality parameters. Two different irrigation amounts (IA-I and IA-II) based on growth stages, in addition to a non-irrigated (rain-fed) control, along with two different BL applications [normal bud load based on traditional pruning practices (1BL) and double bud load (2BL)] were evaluated over a two-year experiment for their effects on the biochemical composition of the berries. Berries from the rain-fed vines had higher sugar levels, whereas no significant change was detected in organic acid levels. The increased bud load (2BL) treatment yielded less sugar in the berries compared to the 1BL control in both years. The total non-colored phenolic compounds (NPC) were greater in the irrigated (especially IA-I) and 2BL treatments than in those of the rain-fed and 1BL control. However, total anthocyanin was greater in the non-irrigated and 1BL control than in the irrigated and 2BL treatments. The antioxidant contents of the berries also varied according to the treatments and years. Our results implied that implementing a higher bud load along with the IA-I irrigation application, in which irrigation applications were 50 and 75% of the cumulative evaporation from the Class A pan during berry set to veraison and veraison to harvest growth stages, respectively, can help in obtaining greater yields in high-plateau viticulture. Thus, if more buds are left on the vines, along with sufficient irrigation and rainfall, yield may increase while maintaining or increasing the biochemical composition of the berries.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.234-242
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• 2019

We analyzed the anthocyanin accumulation, abscisic acid (ABA), gibberellic acid (GA) contents and metabolic genes expression in berry skins under high temperature (High T) at veraison, in order to investigate the cause of bad coloration of 'Kyoho' grape due to High T in summer season. The coloration of 'Kyoho' grapes was stopped by High T for 10 days from veraison, and the fruit quality was not affected except skin color. Total anthocyanin of skins was decreased by High T treatment and malvidin and peonidin were decreased compared to control. In berry skins, ABA content did not decrease by High T treatment, but it was rather higher than that of control. GA content was increased about two times compared to the control after 10 days of High T treatment, which caused decreased ratio of ABA/GA. Analysis of expression of anthocyanin biosynthetic genes showed that the early biosynthetic genes were not affected by High T and the expression of UFGT was decreased by temperature treatment. ABA biosynthetic gene expressions were not affected by High T and the expression of GA20ox1 and GA2ox1/2, which are known to regulate the biosynthesis and inactivation of GA, were increased and decreased by High T, respectively. Therefore, the bad coloration of 'Kyoho' grapes under the High T at veraison was due to inhibition of anthocyanin biosynthesis of skin, and it was suggested that the anthocyanin biosynthesis was controlled by the ratio of ABA and GA rather than ABA content.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.692-700
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• 2016

The objective of this study was to determine the differences in fruit growth, fruit quality, and particularly the pedicel vascular bundles of 'Shigyoku' and 'Heukboseok' grapes, which appeared to be different in softening at harvest. 'Shigyoku' grape matured faster (by about 20 days) than 'Heukboseok' grape with slight fruit enlargement after veraison. However, fruit of 'Heukboseok' grapes showed remarkable enlargement in both the primary and secondary fruit enlargement periods. Hypodermal cell layers were not different after veraison in 'Shigyoku' grape, but degradation of the hypodermis cell wall continued in 'Heukboseok' grape, resulting in a gradual decline in firmness. The numbers of hypodermal cell layers in 'Shigyoku' and 'Heukboseok' grapes were 14.2 and 9.0, respectively. The average content of soluble solids in 'Shigyoku' grape ($19.5^{\circ}Brix$) was significantly ($p{\leq}0.01$) higher than that of 'Heukboseok' grape ($17.0^{\circ}Brix$). Xylem of the pedicel did not differ between the two varieties. However, average phloem area after veraison of 'Shigyoku' grape ($19044.8{\mu}m^2$) was about 1.8 fold greater than that of 'Heukboseok' grape ($10509.4{\mu}m^2$), based on the number of cells constituting the phloem. The cell number and area of the phloem might affect the accumulation of sugars, the main constituents of the cell wall, thus maintaining the firmness of grapes until late maturity. Therefore, the increased softening of 'Heukboseok' grapes at harvest might due to their phloem structure.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.381-386
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• 2010

The berry growth and pericarp characteristics were characterized to confirm the effects of bagging periods on berry cracking during berry development in 'Kyoho' grape. The berry weight was the highest at 13.4 g in late period of bagging treated at 7 to 9 weeks after full bloom (WAFB) as compared with the lowest of 12.3 g in total period bagging. The berry cracking rate under critical turgor pressure in the non-bagging control was 53.3%, while those of bagging treatments were decreased in the order of 42.7%, 37.3%, 33.3%, and 18.7% in bagged during 3 to 9, 3 to 5, 5 to 7, and 7 to 9 WAFB, respectively. In the results of observation on histological characteristics of pericarp, berry lenticels of whole bagging treatments had smaller and normal shape compared with non-bagging control treatment. Especially on the pericarp of late period bagged during 7 to 9 WAFB, suberization around stomata and micro-cracking were not observed and structural strength of pericarp was increased with thicker sub-epidermal layer and cell wall. Therefore, the results indicate that bagging treatment for two weeks just before the veraison when the day length and daylight is relatively longer and stronger can effectively reduce berry cracking by strengthening structure of pericarp in 'Kyoho' grape.