Genomic Informed Breeding Strategies for Strawberry Yield and Fruit Quality Traits

Abstract

Over the last two centuries, breeders have drastically modified the fruit quality of strawberries through artificial selection. However, there remains significant variation in quality across germplasm with scope for further improvements to be made. We reported extensive phenotyping of fruit quality and yield traits in a multi-parental strawberry population to allow genomic prediction and quantitative trait nucleotide (QTN) identification, thereby enabling the description of genetic architecture to inform the efficacy of implementing advanced breeding strategies. A negative relationship (r = −0.21) between total soluble sugar content and class one yield was identified, indicating a trade-off between these two essential traits. This result highlighted an established dilemma for strawberry breeders and a need to uncouple the relationship, particularly under June-bearing, protected production systems comparable to this study. A large effect of quantitative trait nucleotide was associated with perceived acidity and pH whereas multiple loci were associated with firmness. Therefore, we recommended the implementation of both marker assisted selection (MAS) and genomic prediction to capture the observed variation respectively. Furthermore, we identified a large effect locus associated with a 10% increase in the number of class one fruit and a further 10 QTN which, when combined, are associated with a 27% increase in the number of marketable strawberries. Ultimately, our results suggested that the best method to improve strawberry yield is through selecting parental lines based upon the number of marketable fruits produced per plant. Not only were strawberry number metrics less influenced by environmental fluctuations, but they had a larger additive genetic component when compared with mass traits. As such, selecting using “number” traits should lead to faster genetic gain.

Multivariate Contrasts of Seven Strawberry Cultivars in Soilless Cultivation and Greenhouse in Southern Brazil

“…Despite the extensive improvement of strawberries in recent years, there is still a large variation in fruit quality, both within and among cultivars, due to the influence of environmental factors and adopted production systems [51,52]. Prat et al [46] reported improvements in the organoleptic quality of fruits in soilless cropping systems.…”

Feeding the world: impacts of elevated [CO2] on nutrient content of greenhouse grown fruit crops and options for future yield gains

“…Methods of improving these traits including breeding, by exploiting the potential of crop wild relatives as a source of new traits, and/or the genetic manipulation/genome editing of specific traits. There is already evidence that substantial genetic variation exists within wild relatives of fruiting crops [ 100–102 ], which are now studied as a source of crop improvement in various breeding programs [ 103 ]. Further evidence that even in elite material, significant variation is observed in photosynthetic traits.…”

If you go down to the woods today you're in for a big surprise: mapping the diverse phenotypes of the European woodland strawberry

“…It is widely distributed in the Northern Hemisphere being present across Eurasia and Eastern North America (Hilmarsson et al., 2017), and is a rich, but untapped, resource for genetic and metabolic diversity relevant to strawberry breeding programs. The shape and size of strawberry fruit (more technically, the fleshy receptacle) are under hormonal control and the genetic basis underlying these traits as well as quality traits influencing flavor and aroma have begun to be unraveled (Cockerton et al., 2021).…”