THE STATUS OF STRAWBERRY BREEDING AND CULTIVATION IN JAPAN
The first Japanese strawberry cultivar, Fukuba, was selected in 1899 from seedlings of General Chanzy. Most of the Japanese forcing strawberry cultivars have Fukuba in their ancestry. In general, the forcing cultivars have been raised from crosses among Japanese cultivars. American or European cultivars have rarely been used as breeding material in recent years. The present Japanese strawberry breeders are, however, concerned about the increase in inbreeding coefficient in Japanese strawberry cultivars and are suggesting that foreign gene sources should be used more for improvement of the forcing cultivars. Originally, Japanese strawberries were produced under open field culture, in which the fruits were harvested only in May. In Japan today, strawberry fruits are harvested all year round thanks to the development of various techniques that advance the harvesting time. However, production costs have also risen. Consequently, rationalization, such as cost reduction, is required for the forcing culture. Most of the cultivars used in summer-autumn culture are of an everbearing type. The everbearing cultivars differ in flowering behavior, namely, the strength of everbearing. In studies conducted on everbearing strength and the inheritance of the everbearing trait, we found that the node position of the first inflorescence in first-year runner plants is a suitable evaluation criterion for everbearing strength, and that the everbearing habit is regulated by a single dominant gene.
Morishita, M. (2014). THE STATUS OF STRAWBERRY BREEDING AND CULTIVATION IN JAPAN. Acta Hortic. 1049, 125-131
forcing culture, summer-autumn harvesting culture, June-bearing, everbearing