Euphytica 126(2): 177-184. (2002)
Utilizing wild Fragaria virginiana in strawberry cultivar development:
inheritance of photoperiod sensitivity, fruit size, gender, female fertility and disease resistance.
Hancock JF, Luby JJ, Dale A, Callow PW, Serce S, and El-Shiek

The genetics of photoperiod sensitivity, flowering date, fruit size, gender, female fertility, and disease resistance were investigated in progeny between sets of elite F. virginiana selections and F. x ananassa cultivars and selections planted at sites in Michigan, Minnesota and Ontario. Progeny means varied considerably for all the production traits. Most notable were the large fruit and high fertility observed in crosses with High Falls 22 at all three sites, and Montreal River 10 in Ontario and Michigan. Fragaria virginiana ssp. virginiana parents yielded progeny with much larger fruit than F. virginiana ssp. glauca parents. General combining ability was significant for all traits at all locations, while specific combining ability was significant for only fruit diameter, ovule set and fruit set in Michigan. Overall, the highest number of day-neutral genotypes were detected in Ontario (mean =44%) compared to Minnesota (31%) and Michigan (26%). In progeny populations of day-neutral F. x ananassa x short-day F. virginiana almost all fit the 1:1 ratio expected if day-neutrality is regulated by a single dominant gene; however, only a few families of short-day F. x ananassa x day-neutral F. virginiana crosses fit a 1:1 ratio. Likewise, in progeny of day-neutral F. virginiana x day-neutral F. x ananassa crosses, only a few of them fit the 3:1 ratio expected if day-neutrality is regulated by a single dominant gene. These data suggest that it should be relatively easy to use F. virginiana germplasm in strawberry cultivar improvement, and that several different sources of day-neutrality may exist in natural populations.