포도 ‘거봉’ 품종의 변색기 야간 온도 처리가 과피 착색에 미치는 영향

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°C 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°C treated vines, followed by that in 24°C treated vines, than that in 21°C treated vines. Cluster and berry weight and soluble solids content was lower in 24 and 27°C treated vines than in 21°C treated vines. Anthocyanin started to accumulate from 60 DAFB in berry skin of 21°C 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°C treated vines; however, peonidin did not decrease in 24°C treated vines compared to that in 21°C treated vines. Abscisic acid (ABA) peaked at veraison in berry skins of 21°C treated vines and decreased thereafter until 100 DAFB. The increase in ABA content was inhibited in berry skins of 24 and 27°C treated vines. Gibberellin (GA) content in berry skins decreased rapidly at veraison, with the decrease being slower under 27°C than under 21°C. ABA/GA in berry skins of 21°C treated vines peaked at 60 DAFB and decreased thereafter until 100 DAFB. However, ABA/GA decreased in berry skins of 24 and 27°C treated vines, with reduced anthocyanin accumulation. Therefore, high night temperature (above 24°C) 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.