Dihydroisocoumarin Content and Phenotyping of Hydrangea macrophylla subsp. serrata Cultivars under Different Shading Regimes

Hortensias (Hydrangea macrophylla L.) are well known as ornamental plants with their impressive flowers. Besides being an plant, some hortensia species contain constituents of nutritional and pharmaceutical interest. In this context, H. subsp. serrata contains dihydroisocoumarins (DHCs), in particular hydrangenol (HG) phyllodulcin (PD), which determine produce quality. For the successful cultivation serrata, shading may be required. The response a source for DHCs was investigated two growing seasons using three different cultivars (‘Amagi Amacha’, ‘Oamacha’ ‘Odoriko Amacha’) under light conditions: no shade (100% photosynthetic active radiation, PAR), partial (72% PAR) full (36% PAR). regimes had significant effect on dihydroisocoumarin content leaf dry matter each single cultivar. However, ‘Amagi Amacha’ yielded significantly higher PD comparison to showed, contrast, highest HG content. total biomass not affected by regime, but slightly observed partially shaded full-shade conditions. Hyperspectral vegetation indices (VIs) color measurements indicate less vital While lighting is important growth factor production, DHC cultivar dependent.