Usefulness of FaPFRU-Associated Perpetual Flowering Markers in the Cultivated Octoploid Strawberry

The objective of this study was to evaluate four simple sequence repeat (SSR) markers linked to the FaPFRU Perpetual Flowering (PF) locus for ability to predict this trait in populations with different sources of PF such as: F. virginiana subsp. glauca Wasatch clone represented by ‘Capitola’, ‘Tribute’, and ‘Seascape’; ‘Pan American’ source represented by two genetically different individuals of ‘Fort Laramie’ we refer to as ‘Fort Laramie1’, and Fort Laramie2’; and an unknown source represented by ‘Sarian’, ‘Seascape’. Flowering phenotypic data was collected in Michigan and Oregon from 2011 to 2013. Plants were considered PF if they flowered in the spring and after July 17 (the evaluation date over 21 days past the longest day of the year). In 2013, the number of flower trusses and the number of flowers per truss were counted, cut and counted again after four weeks. The allele associated with PF in Bx089 was shared among three of the four strawberry subgenomes and was not effective in predicting PF. Markers Bx215, Bx056, and Bx063 were equally predictive in ‘Capitola’-derived germplasm where association with PF phenotype ranged from 50% in Oregon (2012) to 89% in Michigan (2013). Bx215 was more predictive of PF than the other two markers in ‘Tribute’- (42% to 94%) and ‘Seascape’-derived (50% to 94%) germplasm. Bx215 and Bx063 were equally effective in ‘Fort Laramie2’-derived germplasm but none of the three markers were predictive in ‘Fort Laramie1’- or ‘Sarian’-derived individuals. In general, while Bx215 was most effective in predicting PF in 425 to 94% of individuals that descended from the Wasatch source and ‘Fort Laramie2’, the absence of the markers predicted absence of PF in > 90% of this germplasm and could be used to eliminate once flowering seedlings. This study illustrates the need to test markers in diverse germplasm to establish their usefulness in marker-assisted breeding.