Flowering phenology in a Eucalyptus loxophleba seed orchard, heritability and genetic correlation with biomass production and cineole: breeding strategy implications

Sci Rep. 2020 Sep 17;10(1):15303. doi: 10.1038/s41598-020-72346-3.

Abstract

Reproductive synchronicity within a seed orchard facilitates gene exchange and reduces self-fertilisation. Here we assessed key flowering traits, biomass and foliar 1,8-cineole concentrations of Eucalyptus loxophleba (subsp. lissophloia and gratiae) in an open-pollinated seed orchard. Monthly flowering observations were made on 1142 trees from 60 families and nine provenances across 2 years. The percentage of trees flowering in both years was similar at 87%. There were differences between provenances and families within provenances for flowering traits, biomass and 1,8-cineole and interactions between provenances and year for flowering traits. Heritability of start and end flowering, and 1,8-cineole were high to moderate ([Formula: see text] = 0.75-0.45) and duration of flowering, propensity to flower and biomass estimates were moderate to low ([Formula: see text] = 0.31-0.10). Genetic and phenotypic correlations between flowering traits were high (rg = 0.96-0.63 and rp = 0.93-0.34) except between duration and end of flowering. The correlations were weaker between flowering traits and biomass or 1,8-cineole. 'Dual flowering', when trees underwent two reproductive cycles in a year, was responsible for out-of-phase flowering and those with low biomass and 1,8-cineole concentration should be removed from the breeding programme to hasten selection for desirable traits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomass
  • Breeding / methods
  • Eucalyptol / metabolism*
  • Eucalyptus / genetics*
  • Eucalyptus / metabolism
  • Eucalyptus / physiology*
  • Flowers / genetics*
  • Flowers / metabolism
  • Flowers / physiology*
  • Phenotype
  • Pollination / genetics
  • Pollination / physiology
  • Reproduction / genetics
  • Reproduction / physiology
  • Seeds / genetics
  • Seeds / metabolism
  • Seeds / physiology
  • Self-Fertilization / genetics
  • Self-Fertilization / physiology

Substances

  • Eucalyptol