Identification and Validation of Quantitative Trait Loci Associated with Fruit Puffiness in a Processing Tomato Population

TL;DR

This study identifies and validates genetic regions linked to fruit puffiness in tomatoes, which can help improve fruit quality for processing and fresh markets.

Contribution

The study validates a QTL on chromosome 1 for fruit puffiness and shows its dominance and utility in marker-assisted selection.

Findings

QTLs for fruit puffiness were detected on chromosomes 1, 2, and 4.

The QTL on chromosome 1 explained 22.5% of the variance in puffy fruit and was validated in progeny.

Marker-assisted selection for the QTL on chromosome 1 was as effective as genomic selection in reducing puffiness.

Abstract

Physiological disorders impact the yield and quality of marketable fruit in tomato. Puffy fruit caused by cavities inside the locule can be problematic for processing and fresh market quality. In this paper, we used a recombinant inbred line (RIL) and three derived processing tomato populations to map and validate quantitative trait loci (QTLs) for fruit puffiness across environments. Binary interval mapping was used for mapping the incidence of fruit puffiness, and non-parametric interval mapping and parametric composite interval mapping were used for mapping severity. Marker–trait regressions were carried out to validate putative QTLs in subsequent crosses. QTLs were detected on chromosome (Chr) 1, 2, and 4. Only the QTL on Chr 1 was validated in progeny from subsequent crosses. This QTL explained up to 22.5% of the variance in the percentage of puffy fruit, with a significant interaction between loci on Chr 2 and 4, increasing the percentage of puffy fruit by an additional 15%. The allele responsible for puffy fruit on Chr 1 was inherited from parent FG02-188 and was dominant towards increased incidence and severity. Marker-assisted selection (MAS) for the QTL on Chr 1 was as efficient as genomic selection (GS) in reducing the incidence and severity of puffy fruit, despite the potential contribution of other loci.

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