Characterization of anthocyanin and proanthocyanidin biosynthesis in two strawberry genotypes during fruit development in response to different light qualities

LED-based light sources that can provide narrowly-centered spectrum have been frequently applied to manipulate the plant growth, development and metabolism in recent years. This study aimed to find out the effect of different light qualities on the production of anthocyanins and proanthocyanidins. The results showed RL (red light), BL (blue light), RBL (red light: blue light = 1:1) induced the strawberry fruit coloration earlier by increasing the content of total anthocyanins as a result of high expression of related genes, which was also concluded from a*, C*, h degrees values in 'Tokun' at 28 DAF, and RBL significantly promoted anthocyanin and proanthocyanidin biosynthesis in these two strawberry genotypes during fruit development. Simultaneously, the contents of anthocyanins and proanthocyanidins in 'Toyonaka' were also remarkably upregulated by BL and RL, respectively, indicating different strawberry genotypes to some extent probably had a distinct response to light quality. Hence, genotype factor should be taken into consideration when supplement of light quality was used as practical application in strawberry cultivation. Taken together, this study provided an insight into a further understanding of roles of light quality in the color formation for strawberry and a potential means to increase the health-related values of strawberry through altering the anthocyanin and proanthocyanidin contents of the fruit.