Farm Forestry New ZealandEvaluation of multi-site progeny test in Eucalyptus fastigata
By Jaroslav Klapste, Toby Stovold, Peter Bird, Kane Fleet, June 2023.
Download SWP-T163 (pdf)
Executive summary
Progeny trials for Eucalyptus fastigata in the third cycle, planted in 2009 and 2012 in Kaingaroa (compartment 333 and 605), Waihaha and Waihapua were assessed at age of 8 for growth and form characteristics. As these trials have now reached an age when selections for the next generation can be made, it is required to acquire measurements for genetic evaluation and selection purposes prior to the thinning process.
This investigation aimed to carry out a multi-environmental genetic evaluation to estimate genetic parameters such as heritability, genetic correlations across phenotypes within sites, and genotype by environment interactions across investigated sites. Additionally, a list of breeding values was compiled for the purpose of selecting the individuals who would form the next generation of seed orchards and breeding populations.
As a result, the favourable correlation structure makes it possible to simultaneously select productive individuals that have high wood stiffness (approximated by acoustic velocity) and a favoured branching pattern. The inclusion of stem straightness (STR) and malformation (MAL) into the selection will be more restricted due to the modest but favourable genetic correlations they have with DBH.
Genotype by environment interaction (GxE) analysis showed a substantial positive genetic correlation between FR503/1 and FR503/2 across most of the studied traits. However, these two sites exhibited unfavourable genetic correlation with FR503/3, which is geographically adjacent to FR503/1. Due to FR503/3's poor site quality and lack of genetic linkage with FR503/1 and FR503/2, we presume the negative genetic correlations should be interpreted with caution. We recommend implementing multi-generational evaluation to increase the genetic connectivity of FR503/3 and FR503/4 with the rest of the breeding programme to improve the quantification of GxE.
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