Segregation ratio in selfed and crossed progenies demonstrates single dominant gene inheritance of day-neutrality in strawberry

Studies on the inheritance of day-neutrality, a highly desirable trait in strawberry (Fragaria×ananassa), have not been conclusive because flowering phenotypes were evaluated based on different materials and experimental sites. In the present study, selfed and crossed progenies of Day-neutral (DN) ‘Albion’ and June-bearing (JB) ‘Akihime’ cultivars, namely ‘Albion’ × ‘Albion’, ‘Akihime’ × ‘Akihime’, and ‘Akihime’ × ‘Albion’, were established in 2013 and 2014. The flowering phenotype (DN or JB) of seedlings from each of the three progenies, as well as of parental plants, was evaluated for two successive years (2015 and 2016) in Central Yunnan, China, and their segregation ratios were used to elucidate day-neutrality inheritance. Single dominant gene inheritance was demonstrated for day-neutrality, although minor genes (from the JB parent ‘Akihime’) likely increase DN magnitude. During the juvenile stage (i.e., long before the first inflorescence), the major gene controlling day-neutrality may not be expressed. We provide basic information for DN gene mapping and cloning, as well as materials (progenies) for domestic DN strawberry breeding.