Molecular characterization of intergeneric hybrids between Malus and Pyrus

Abstract

Apple (Malus) and pear (Pyrus) are economically important fruit crops well known for their unique textures, flavours, and nutritional qualities. Both genera are characterised by a distinct pattern of secondary metabolites, which directly affect not only resistance to certain diseases, but also have significant impacts on the flavour and nutritional value of the fruit. The identical chromosome numbers, similar genome size, and their recent divergence date, together with DNA markers have shown that apple and pear genomes are highly co-linear. This study utilized comparative genomic approaches, including simple sequence repeats, high resolution single nucleotide polymorphism melting analysis, and single nucleotide polymorphism chip analysis to identify genetic differences among hybrids of Malus and Pyrus, and F2 offspring. This research has demonstrated and validated that these three marker types, along with metabolomics analysis are very powerful tools to detect and confirm hybridity of progeny derived from crosses between apple and pear in both cross directions. Furthermore, this work analysed the genus-specific metabolite patterns and the resistance to fire blight (Erwinia amylovora) in progeny. The findings of this work will enhance and accelerate the breeding of novel tree fruit crops that benefit producers and consumers, by enabling marker assisted selection of desired traits introgressed between pear and apple.

Assessment and Partial Characterization of Candidate Genes in Dihydrochalcone and Arbutin Biosynthesis in an Apple–Pear Hybrid by De Novo Transcriptome Assembly

“…Intergeneric hybrids of Malus and Pyrus have been previously attempted, aiming to introduce novel traits from apple and pear relevant to new breeding programs. Although promising as a germplasm resource, several attempts of intergeneric hybrids frequently lead to nonviable or sterile progeny . The cross made by Max Zwintzscher between M. × domestica cv.…”

“…“Kalco” and a P. communis descendant from “Andrè Desportes” resulted in a fertile intergeneric hybrid, which exhibits intermediate characteristics from apples and pears, including the accumulation of both genus-specific phloridzin and arbutin . The accumulation of apple- and pear-characteristic compounds in an intergeneric hybrid represents a useful genetic resource for getting a better understanding of the biosynthesis of such natural compounds, which could serve as the basis for assessing their physiological role.…”