Tree Genetics & Genomes

, Volume 4, Issue 4, pp 715–725

Mapping species differences for adventitious rooting in a Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid

  • Mervyn Shepherd
  • Shabana Kasem
  • David J. Lee
  • Robert Henry
Original Paper

DOI: 10.1007/s11295-008-0145-1

Cite this article as:
Shepherd, M., Kasem, S., Lee, D.J. et al. Tree Genetics & Genomes (2008) 4: 715. doi:10.1007/s11295-008-0145-1

Abstract

Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation. Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene action more broadly in hybrids between these species for some traits.

Keywords

QTL mapping Propagation Species effects 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Mervyn Shepherd
    • 1
    • 2
  • Shabana Kasem
    • 1
  • David J. Lee
    • 3
  • Robert Henry
    • 1
    • 2
  1. 1.Centre for Plant Conservation GeneticsSouthern Cross UniversityLismoreAustralia
  2. 2.Cooperative Research Centre for ForestrySouthern Cross UniversityLismoreAustralia
  3. 3.Department of Primary Industries and FisheriesHorticulture and Forestry ScienceGympieAustralia

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