Pacbio Sequencing Reveals Identical Organelle Genomes between American Cranberry (Vaccinium macrocarpon Ait.) and a Wild Relative.

Luis Diaz-Garcia,Jessica Rohde,Juan Zalapa,Tyler Smith,Lorraine Rodriguez-Bonilla

doi:10.3390/genes10040291

Abstract

Breeding efforts in the American cranberry (Vaccinium macrocarpon Ait.), a North American perennial fruit crop of great importance, have been hampered by the limited genetic and phenotypic variability observed among cultivars and experimental materials. Most of the cultivars commercially used by cranberry growers today were derived from a few wild accessions bred in the 1950s. In different crops, wild germplasm has been used as an important genetic resource to incorporate novel traits and increase the phenotypic diversity of breeding materials. Vaccinium microcarpum (Turcz. ex Rupr.) Schmalh. and V. oxycoccos L., two closely related species, may be cross-compatible with the American cranberry, and could be useful to improve fruit quality such as phytochemical content. Furthermore, given their northern distribution, they could also help develop cold hardy cultivars. Although these species have previously been analyzed in diversity studies, genomic characterization and comparative studies are still lacking. In this study, we sequenced and assembled the organelle genomes of the cultivated American cranberry and its wild relative, V. microcarpum. PacBio sequencing technology allowed us to assemble both mitochondrial and plastid genomes at very high coverage and in a single circular scaffold. A comparative analysis revealed that the mitochondrial genome sequences were identical between both species and that the plastids presented only two synonymous single nucleotide polymorphisms (SNPs). Moreover, the Illumina resequencing of additional accessions of V. microcarpum and V. oxycoccos revealed high genetic variation in both species. Based on these results, we provided a hypothesis involving the extension and dynamics of the last glaciation period in North America, and how this could have shaped the distribution and dispersal of V. microcarpum. Finally, we provided important data regarding the polyploid origin of V. oxycoccos.

Highlights

IntroductionThe majority of food crops derive from a few wild plant species
Worldwide, the majority of food crops derive from a few wild plant species
Few crop species are native to North America, and even fewer can still be found in their wild forms and habitats

Summary

Introduction

The majority of food crops derive from a few wild plant species. In the United States (USA), farmers grow a great variety of plants such as cereals, sugar crops, vegetables, and fruits (FAO, 2010). Few crop species are native to North America, and even fewer can still be found in their wild forms and habitats. Especially from crop wild relatives, is of tremendous. (American cranberry) is endemic to North America, and one of the few fruit crops that can still be found in the wild. The niche of this species is similar to its wild relative

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Results

Conclusion