Molecular markers in Carya illinoinensis (Juglandaceae): from genetic characterization to molecular breeding

Carya illinoinensis (pecan) is a fruit crop native to Mexico and the USA and cultivated across the world. Despite the advances of the molecular markers' technologies and their use in genetic studies of diversity and breeding, studies with this species only reticently accompanied this progress. Here we review the studies using molecular markers, the gaps, and the perspectives concerning these technologies in pecaniculture. The selection of plants more adapted to the particular conditions where the species is cultivated and the obligatory outcrossing mode of reproduction lead the species to generate several new genetic combinations. Molecular markers were employed to assess this diversity, using PCR-based markers and sequencing-based technologies. Genetic diversity was characterised in natural populations and collections of pecan germplasm. Markers putatively linked to traits of interest were reported and the genome sequencing technology provided insights into the evolution of the species. The outcomes of these studies still have to be integrated and further exploited to reach and impact the orchards and breeding programmes. However, the scientific advances in molecular markers research and the growth of the pecan's supply chain may drive to a scenario in which these biotechnologies will become tools regularly assisting breeders and farmers.

Automated summary

Research using molecular markers in pecan mainly focuses on genetic diversity and breeding, with the need to further integrate study outcomes to better impact orchards and breeding programs. The scientific advances in molecular markers research and the growth of the pecan's supply chain may lead to these biotechnologies becoming regularly used tools for breeders and farmers.