Association Of Allelic Variation In Xylem Genes With Wood Properties In Eucalyptus Nitens

We used association studies to identify allelic variation in genes that influence wood fibre development in Eucalyptus nitens (Deane & Maiden). Genes selected for analysis were differentially expressed in wood with contrasting properties such as cellulose and lignin content, pulp yield and microfibril angle (MFA). Single nucleotide polymorphisms (SNPs) were identified by sequencing the candidate genes in a number of unrelated individuals. Selected SNPs were genotyped across 420 unrelated E. nitens trees from central Victorian populations and growing in a provenance trial at Meunna in north-western Tasmania. Significantly associated SNPs were genotyped across two other populations in northern Tasmania in order to validate associated SNPs. We have compiled a database of phenotypic information relating particularly to wood fibre properties for each individual in the association and validation populations.Associations between SNPs and wood properties were identified by comparing trait means in different SNP genotype classes. Several significantly associated SNPs identified in the Meunna population were validated in the other populations. The direction of the allele effect was reversed for two SNPs that were associated with kraft pulp yield. DNA markers identified in this research may be used to complement existing selection methods in breeding programs.