(267) A Rapid Transformation System for Octoploid Strawberry

Cultivated strawberry ( Fragari × ananassa ) is a valuable crop, yet has benefitted little from recent advances in biotechnology and genomics. A high-throughput system for transformation and regeneration would hasten elucidation of gene function for strawberry and possibly the Rosaceae in general. In this report, a protocol for high-frequency octoploid strawberry transformation and regeneration is presented. The protocol uses leaf, petiole, and stolon as explants from a newly selected genotype, `Laboratory Festival #9'. This genotype was selected from progeny of a `Strawberry Festival' self-cross exclusively for its rapid regeneration and robust growth in culture. Direct organogenesis has been achieved from the leaf or from prolific callus with multiple shoots being visible in as few as 14 days. Over 100 viable regenerants may be obtained from a single leaf explant of about 3-cm 2 size. This laboratory-friendly genotype allows high-throughput, statistically relevant, studies of gene function in the octoploid strawberry genetic background as well as generation of large transgenic populations.