ブドウ'安芸クイーン'における果皮の深色化に及ぼす着果量の影響(発育制御)  [in Japanese] Effect of Crop Load on the Expression of Deep Color in 'Aki Queen' Grape Berry(Growth Regulation)  [in Japanese]

ブドウ'安芸クイーン'では, 果皮が深色化して品種特性の鮮赤色ではない暗赤色な果粒がしばしば出現する.鮮赤色な適着色果房の生産性を向上させるために, 果色に着果量が及ぼす影響を調べた.着色開始前の満開後32日に摘粒, 摘心および新梢基部の環状剥皮処理を行い, 1葉あたりの果粒数を0.14, 0.52, 1.53, 2.47の4段階に設定した.0.14区と0.52区では, 果皮のアントシアニン総量は処理後, 著しく増加し, 満開後76日には深色化果粒が多く発生した.一方, 1.53区では, アントシアニン生成が抑制され, 満開後96日に主に適着色果粒が生産された.2.47区ではアントシアニンの生成が不十分であり着色不良となった.アントシアニン組成と果皮の深色化には明確な関係は認められなかった.以上より, 着果量調整により果皮のアントシアニン生成を制御して適着色果粒を安定生産できると考えられた.

'Aki Queen' is a bright-red grape cultivar, but often bears an undesirable deep berry-colored grape. To improve the productivity of clusters with the desired color, the effects of crop load on coloration were investigated in 'Aki Queen' grape. Berry numbers per a leaf were adjusted to 0.14, 0.52, 1.53 and 2.47 by pinching and berry thinning at 32 days after anthesis, and girdling treatement was conducted at the base of the shoot. In plants with 0.14 and 0.52 fractions, total anthocyanin concentrations in the skin of the berry increased over 50×10^<-6>g・cm^<-2> and deep colored berries appeared frequently 76 days after anthesis. The 1.53 fraction, however, bore proper bright red berries with an anthocyanin concentration of about 25×10^<-6>g・cm^<-2> 96 days after anthesis. The 2.47 fraction showed slight anthocyanin concentration, resulting in poor coloration. However, we could not find a clear relationship between anthocyanin composition and deep coloration. These data suggest that controling the crop load could adjust 'Aki Queen' berry to the proper coloration through regulation of anthocyanin concentration.