Identification and validation of FaP1D7, a putative marker associated with the biosynthesis of methyl butanoate in cultivated strawberry (Fragaria x ananassa)

Mian Chee Gor,Edwin Pang,Thishakya De Silva,Chrishani Candappa,Nitin Mantri

doi:10.1038/s41598-017-17448-1

Abstract

Breeding strawberry (Fragaria x ananassa) with enhanced fruit flavour is one of the top breeding goals of many strawberry-producing countries. Although several genes involved in the biosynthetic pathways of key aroma compounds have been identified, the development and application of molecular markers associated with fruit flavour remain limited. This study aims to identify molecular markers closely linked to genes controlling strawberry aroma. A purpose-built Subtracted Diversity Array (SDA) known as Fragaria Discovery Panel (FDP) was used for marker screening. Polymorphic sequences associated with key aroma compounds were identified from two DNA bulks with extreme phenotypes, established using 50 F1 progeny plants derived from Juliette X 07-102-41 cross, two strawberry genotypes differing in aroma profile. A total of 49 polymorphic markers for eight key aroma compounds were detected using genotypic data of the extreme DNA bulks and phenotypic data obtained from gas chromatography-mass spectrometry (GC-MS). A similarity search against the physical maps of Fragaria vesca revealed that FaP1D7 is linked to genes potentially involved in the synthesis of methyl butanoate. A C/T SNP was detected within the feature, which could possibly be converted to a molecular tool for rapid screening of the strawberry accessions for their methyl butanoate production capacity.

Highlights

Some studies suggest that the flavour quality of many fruits including strawberry has deteriorated due to conventional breeding practices[1,2]
We recently developed a Subtracted Diversity Array (SDA)[23] called Fragaria Discovery Panel (FDP) as a platform for screening molecular markers associated with agronomically important traits[24]
We report the identification of a putative marker allele, FaP1D7 using an in-house developed subtracted gDNA microarray

Summary

Introduction

Some studies suggest that the flavour quality of many fruits including strawberry has deteriorated due to conventional breeding practices[1,2]. Furaneol and mesifuranne have been described as the two most important compounds contributing to the sweet and caramel-like flavour in ripe strawberry fruits[9,10,11]. Strawberry flavour research has progressed from chemical and sensory analyses to the investigation of biosynthesis and genetic control of important aroma compounds[13]. Two recent studies have shown that a fatty acid desaturase FaFAD1 gene was correlated with the production of γ-decalactone in strawberry fruit[21] and a PCR-based marker co-segregating with the phenotype was developed[22]. Despite the development of PCR-based markers for linalool and γ-decalactone, breeding for improved strawberry flavour has been relatively slow due to the complex genetic control of fruit flavour biogenesis. We extended the utility of the subtracted gDNA microarray-assisted BSA for the identification of polymorphic markers linked to the loci determining strawberry aroma

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Conclusion