Abstract

The flowering process in Fragaria x ananassa has been widely studied, while the favourable environmental conditions for Fragaria chiloensis subsp. chiloensis f. chiloensis, the "Chilean white strawberry', are not well understood. With the objective to study the floral induction and dormancy process in this species, several experiments were conducted from 2016 to 2019 using the ecotype `Contulmo' for 'Chilean white strawberry' and the cv. 'Camarosa' for F. x ananassa, the latter as a reference genotype. Growth parameters and the differentiation state of apex were evaluated at two locations in Chile (33 degrees 38' S and 38 degrees 45' S) as well as in climate-controlled growth chamber (9 degrees C and 8 -h photoperiod). Additionally, the chilling requirement for dormancy release after different cold storage periods (2 degrees C in darkness) was determined in this species. This requirement was field-verified (38 degrees 45' S) over two seasons. The 'Chilean white strawberry' showed continuous and reduced growth, without changes under different temperature and photoperiod conditions, with values significantly different from those of cv. 'Camarosa' . In both locations, the floral and dormancy induction started late (June), occurred only in a part of the plants (20-30%) and them yielded a single inflorescence. In addition, it was determined that the 'Chilean white strawberry' require approximately 900-1,000 chilling units for dormancy release. Our results indicated that flowering is favoured only with low temperatures, lower than those necessary for many short-day genotypes. This characteristic, together with the late flowering, suggests that there is a vernalization requirement for this species. Temperature increase is probably the main factor involved in the current floral behaviour of 'Chilean white strawberry', however this can decreasing even more in a climate change context.