Additive QTLs on three chromosomes control flowering time in woodland strawberry (Fragaria vesca L.)

Abstract

Flowering time is an important trait that affects survival, reproduction and yield in both wild and cultivated plants. Therefore, many studies have focused on the identification of flowering time quantitative trait locus (QTLs) in different crops, and molecular control of this trait has been extensively investigated in model species. Here we report the mapping of QTLs for flowering time and vegetative traits in a large woodland strawberry mapping population that was phenotyped both under field conditions and in a greenhouse after flower induction in the field. The greenhouse experiment revealed additive QTLs in three linkage groups (LG), two on both LG4 and LG7, and one on LG6 that explain about half of the flowering time variance in the population. Three of the QTLs were newly identified in this study, and one co-localized with the previously characterized FvTFL1 gene. An additional strong QTL corresponding to previously mapped PFRU was detected in both field and greenhouse experiments indicating that gene(s) in this locus can control the timing of flowering in different environments in addition to the duration of flowering and axillary bud differentiation to runners and branch crowns. Several putative flowering time genes were identified in these QTL regions that await functional validation. Our results indicate that a few major QTLs may control flowering time and axillary bud differentiation in strawberries. We suggest that the identification of causal genes in the diploid strawberry may enable fine tuning of flowering time and vegetative growth in the closely related octoploid cultivated strawberry.

Applying the Solanaceae Strategies to Strawberry Crop Improvement

“…Wide natural and induced genetic diversity (Figure 1) [11] and populations of introgression lines [57] are available, which have already allowed the discovery of causal mutations of the perpetual flowering [29,30] and runnerless [10,11] The exploitation of artificially (Figure 4, Key Figure) induced diversity by mapping-by-sequencing to discover causal mutation is relatively straightforward in both tomato and woodland strawberry [11,58]. Exploitation of natural genetic diversity from woodland strawberry (Figure 1; e.g., for vernalization requirement [59], for fruit shape and flavor [53,57]) can be done by generating various types of populations [10,57,60] and by GWASs, as done in tomato [4][5][6]18,48,49]. For GWASs, the first step is to constitute representative F. vesca collections to control the effect of population structure [17,49].…”

Single-molecule sequencing and optical mapping yields an improved genome of woodland strawberry (Fragaria vesca) with chromosome-scale contiguity

“…S5 ). These types of errors considerably hinder various genomic analyses, including fine-mapping genes underlying traits [ 21 ] and identifying structural variants via comparative genomics. Here we demonstrate the superior quality of F. vesca V4 by making comparisons with a high-density linkage map of Fragaria iinuma e [ 22 ], which is another putative diploid progenitor species of the cultivated octoploid strawberry.…”

Control of Flowering and Runnering in Strawberry

“…Since FvTFL1 is located in this region in the woodland strawberry genome, these data indicate that F. bucharica TFL1 may complement the non-functional TFL1 alleles of 'Reine des Vallees' in this introgression line (Urrutia et al, 2015). Two more QTLs have been identified in a woodland strawberry F 2 mapping population using genotyping-by-sequencing (Samad et al, 2017). Finemapping and gene functional analyses are needed to identify causal genes.…”

“…2). Additional QTLs for runner production have also been found in both woodland strawberry and garden strawberry, but causal genes remain unknown (Samad et al, 2017;Hossain et al, 2019).…”