Effect of grape genotype and tissue type on callus growth and production of resveratrols and their piceids after UV-C irradiation

Grape calli systems were used to study the relationships between stilbene production and: (1) four grape genotypes, (2) leaf, berry exocarp and seed tissues and (3) UV-C irradiation. All explants could be de-differentiated. However, subsequent callus growth depended mainly on genotype and tissue type. Non-embryogenic callus accumulated more resveratrols and piceids and had a higher growth index than pro-embryogenic and embryogenic calli. UV-C irradiation for 20 min was most efficient in promoting both the accumulation of resveratrols and piceids and callus growth index. There was dynamic production of resveratrols and piceids in UV-C-irradiated leaf-derived calli over a 72 h period, with optimum harvest time for the highest total stilbene content at 48 h. Accumulation of stilbenes in UV-C-irradiated calli depended upon genetic background and tissue type, with higher stilbene contents in two interspecific root stocks and leaf or exocarp explants.