03974naa a2200289 a 450000100080000000500110000800800410001902400340006010000160009424501730011026000090028350008770029252021420116965000200331165000110333165000140334265300260335665300290338265300230341165300200343470000180345470000160347270000160348870000160350470000210352077301430354110617562021-02-23       2021    bl uuuu     u00u1 u    #d7 a10.3389/fpls.2021.6268112DOI1 aQUEZADA, M.  aConstruction of a high-density genetic map of Acca sellowiana (Berg.) Burret, an outcrossing species, based on two connected mapping populations.h[electronic resource]  c2021  aArticle history: Received: 06 November 2020; Accepted: 12 January 2021; Published: 23 February 2021. Edited by: Maria Luisa Badenes, Instituto Valenciano de Investigaciones Agrarias, Spain.  Reviewed by: Shouvik Das, Indian Agricultural Research Institute (ICAR), India; Jonathan Elias Maldonado, Pontificia Universidad Católica de Chile, Chile. Correspondence: Antonio Augusto Franco Garcia - augusto.garcia@usp.br Specialty section: This article was submitted to Plant Breeding, a section of the journal Frontiers in Plant Science. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).  This article is part of the research topic: Breeding Innovations in Underutilized Temperate Fruit Trees:  https://www.frontiersin.org/research-topics/14915/breeding-innovations-in-underutilized-temperate-fruit-trees#articles  aABSTRACT. Acca sellowiana, known as feijoa or pineapple guava, is a diploid, (2n = 2x = 22) outcrossing fruit tree species native to Uruguay and Brazil. The species stands out for its highly aromatic fruits, with nutraceutical and therapeutic value. Despite its promising agronomical value, genetic studies on this species are limited. Linkage genetic maps are valuable tools for genetic and genomic studies, and constitute essential tools in breeding programs to support the development of molecular breeding strategies. A high-density composite genetic linkage map of A. sellowiana was constructed using two genetically connected populations: H5 (TCO × BR, N = 160) and H6 (TCO × DP, N = 184). Genotyping by sequencing (GBS) approach was successfully applied for developing single nucleotide polymorphism (SNP) markers. A total of 4,921 SNP markers were identified using the reference genome of the closely related species Eucalyptus grandis, whereas other 4,656 SNPs were discovered using a de novo pipeline. The individual H5 and H6 maps comprised 1,236 and 1,302 markers distributed over the expected 11 linkage groups, respectively. These two maps spanned a map length of 1,593 and 1,572 cM, with an average inter-marker distance of 1.29 and 1.21 cM, respectively. A large proportion of markers were common to both maps and showed a high degree of collinearity. The composite map consisted of 1,897 SNPs markers with a total map length of 1,314 cM and an average inter-marker distance of 0.69. A novel approach for the construction of composite maps where the meiosis information of individuals of two connected populations is captured in a single estimator is described. A high-density, accurate composite map based on a consensus ordering of markers provides a valuable contribution for future genetic research and breeding efforts in A. sellowiana. A novel mapping approach based on an estimation of multipopulation recombination fraction described here may be applied in the construction of dense composite genetic maps for any other outcrossing diploid species. © 2021 Quezada, Amadeu, Vignale, Cabrera, Pritsch and Garcia.  aACCA SELLOWIANA  aFEIJOA  aMYRTACEAE  aComposite genetic map  aGenotyping by sequencing  aMultiparent family  aPineapple guava1 aAMADEU, R. R.1 aVIGNALE, B.1 aCABRERA, D.1 aPRITSCH, C.1 aGARCIA, A. A. F.  tFrontiers in Plant Science, 23 February 2021, Volume 12, Article number 626811. OPEN ACCESS. Doi: https://doi.org/10.3389/fpls.2021.626811