Examining the cause of high inbreeding depression

Analysis of whole-genome sequence data in 28 selfed progeny of Eucalyptus grandis

Philip W. Hedrick, Uffe Hellsten, Dario Grattapaglia

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The genome-wide heterozygosity at 9590 genes, all heterozygous in a single Eucalyptus grandis parent tree, was examined in a group of 28 S1 offspring. Heterozygosity ranged from 52-79%, averaging 65.5%, much higher than the 50% expected under random segregation, supporting the occurrence of strong (47%) selection against homozygosity. The expected pattern of heterozygosity from theoretical calculations and simulations for recessive detrimentals (pseudo-overdominance) and intrinsic heterozygote advantage was examined and compared with that observed. The observed patterns are consistent with at least several detrimental loci with large effects on both parental chromosomes of the 11 pairs. It is likely that 100 or more genes, many with substantial effects on viability, are contributing to this inbreeding depression. Although our genome-wide analysis of nearly 10 000 genes strongly suggested that pseudo-overdominance was responsible for the observed high inbreeding depression, heterozygote advantage could not be excluded. Finding inconvertible evidence of the cause of inbreeding depression still presents a difficult challenge. This study is the first theoretical examination of the genomic effect of inbreeding in a forest tree and provides an approach to analyze these data to determine the extent and cause of inbreeding depression across other plant genomes.

Original languageEnglish (US)
Pages (from-to)600-611
Number of pages12
JournalNew Phytologist
Volume209
Issue number2
DOIs
StatePublished - Jan 1 2016

Fingerprint

Eucalyptus
Eucalyptus grandis
inbreeding depression
heterozygosity
Genome
genome
Heterozygote
overdominance
Genes
Plant Genome
Chromosomes, Human, Pair 11
Inbreeding
genes
homozygosity
forest trees
inbreeding
Inbreeding Depression
viability
chromosomes
genomics

Keywords

  • Eucalyptus grandis
  • Heterozygosity
  • Heterozygote advantage
  • Linkage disequilibrium
  • Pseudo-overdominance
  • Tree
  • Viability

ASJC Scopus subject areas

  • Plant Science
  • Physiology

Cite this

Examining the cause of high inbreeding depression : Analysis of whole-genome sequence data in 28 selfed progeny of Eucalyptus grandis. / Hedrick, Philip W.; Hellsten, Uffe; Grattapaglia, Dario.

In: New Phytologist, Vol. 209, No. 2, 01.01.2016, p. 600-611.

Research output: Contribution to journalArticle

Hedrick, Philip W. ; Hellsten, Uffe ; Grattapaglia, Dario. / Examining the cause of high inbreeding depression : Analysis of whole-genome sequence data in 28 selfed progeny of Eucalyptus grandis. In: New Phytologist. 2016 ; Vol. 209, No. 2. pp. 600-611.
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