Genetic variation for early flowering, survival and growth in sugar gum (Eucalyptus cladocalyx F. Muell) in southern Atacama Desert

Abstract

The aim of this study was to examine the genetic control of time-to-flowering (precocity) in 39 open-pollinated families of Eucalyptus cladocalyx in southern Atacama Desert, Chile, with the view to the selection of trees that flower earlier but with minimal impact on survival and growth. A Bayesian approach, implemented using Gibbs sampling algorithm, was used in data analyses. Precocity was assessed as a binary response at age three and was found to be highly heritable. The estimates of posterior mean and of the 95% posterior interval of the heritability were 0.51 and [0.46-0.56], respectively. Estimated genetic gain ranged from 36.15 to 41.22% (selection intensities of 14.29 and 7.48%, respectively). Total height, basal diameter and survival (measured at age 5) had a positive and relatively moderate genetic correlation with early flowering (r = 0.23, 0.29 and 0.11, respectively) indicating that selection for early flowering alone would have a moderate impact on growth and survival. Early flowering of Eucalyptus cladocalyx was found to be highly heritable in southern Atacama Desert populations, which could be used to improve the honey production in situations where flowers from native species are not available in sufficient quantities.

Bayesian analysis of the genetic structure of a Brazilian popcorn germplasm using data from simple sequence repeats (SSR)

“…According to Latch et al (2006), most of the recent advances in clustering techniques have been made in a Bayesian statistical framework to allow simultaneous estimation of many interdependent parameters in complex models. The advantages of utilizing a Bayesian framework in the analysis of genetic experiments have been emphasized and discussed by several authors (Mora et al, 2009;Cané-Retamales et al, 2011;Li et al, 2011;Safner et al, 2011;Arriagada et al, 2012).…”

Generalized composite interval mapping offers improved efficiency in the analysis of loci influencing non-normal continuous traits

“…For example, binary data are often found when the aim is to improve traits such as disease status (Setiawan et al, 2000;Park et al, 2001), mortality or survival (Mora et al, 2008d), flowering (Missiaggia et al, 2005;Mora et al, 2007;Mora et al, 2009), among other traits. Yang et al (2009) stated that deviations from this assumption may affect the accuracy of QTL detection and lead to detection of spurious QTLs.…”

“…The methods of simple regression, maximum likelihood and those based on Monte Carlo Markov Chains have been frequently used to detect QTLs, which are focused mainly on a continuous distribution (Normal or Gaussian) of the trait of interest (Thomson, 2003). However, several studies related to plant breeding have shown that several traits of economic and scientific interest have non-Gaussian distribution (Spyrides-Cunha et al, 2000;Ribeiro et al, 2005;Mora et al, 2007;Mora et al, 2009).…”

Genetic parameters of growth and survival in Acacia saligna shrubs

“…The predicted genetic gains were estimated using the genetic values of the individual trees (breeding values) according to Mora et al (2009). Ranking with the genetic values were made and the associations between the rankings of each trait by means of the Spearman correlation coefficient, were measured.…”

“…The forest plantation programs are usually intended for high biomass productivity, combining acceptable rates of growth and survival. Subsequently, the survival of trees in juvenile states of development has been a trait of interest in different programs of selection and improvement (Coutinho et al, 2004;Mora et al, 2009;Rodovalho et al, 2008).…”