Parental and Consensus Linkage Maps of Eucalyptus globulus Using AFLP and Microsatellite Markers

Abstract

Parental and consensus maps were constructed in an F2 inter-provenance cross of Eucalyptus globulus, using amplified fragment length polymorphism (AFLP) and microsatellite (or simple sequence repeats [SSR]) markers. The female map had 12 linkage groups and 118 markers, comprising 33 SSR and 85 AFLP loci. The male map had 14 linkage groups and 130 markers comprising 36 SSR and 94 AFLP loci. The integrated map featured 10 linkage groups and 165 markers, including 33 SSR and 132 AFLP loci, a small 11th group was identified in the male parent. Moderate segregation distortion was detected, concentrated in gender specific groups. The strongest distortion was detected in the female parent for which causal mechanisms are discussed. The inclusion of SSR markers previously mapped in several different eucalypt species within the subgenus Symphyomyrtus (E. globulus, E. camaldulensis, and predominantly E. grandis and E. urophylla), allowed comparison of linkage groups across species and demonstrated that linkage orders previously reported in E. globulus, E. grandis and E. urophylla were largely conserved.

QTL influencing growth and wood properties in Eucalyptus globulus

“…The distribution of genotype means were examined for each trait (by the Kolmogorov-Smirnov test using PROC UNIVARIATE of SAS), in order to test the assumption of a normal distribution for QTL mapping. QTL analysis was conducted with MAPQTL 4.0 (Van Ooijen et al 2002), using the consensus linkage map constructed by Freeman et al (2006), comprised of 165 makers, of which 33 were SSR and 132 were AFLP. Putative QTL were declared at two different levels of significance; the genome-wide level (genome-wide type I error <0.05), and the chromosomewide level (chromosome-wide type I error rate <0.05).…”

Few Mendelian Genes Underlie the Quantitative Response of a Forest Tree, Eucalyptus globulus, to a Natural Fungal Epidemic

“…QTL analysis was conducted with MAPQTL 4.0 (Van Ooijen et al 2002), using the consensus linkage map constructed in family 1 (described in detail in Freeman et al 2006). Putative QTL were declared at two different levels, significant (genomewide type I error ,0.05) and suggestive (chromosomewide type I error rate ,0.05).…”

“…Comparative QTL mapping will be particularly useful in a genus such as Eucalyptus, in which QTL mapping is in its infancy. The inclusion of numerous transferable microsatellite markers in the linkage map used for QTL analysis in this study (Freeman et al 2006) will facilitate comparative mapping. The LOD threshold for genomewide significance was determined by permutation testing (1000 replications; Churchill and Doerge 1994).…”

Progress in Myrtaceae genetics and genomics: Eucalyptus as the pivotal genus

“…More informative, codominant markers such as isozymes, RFLPs, and ESTs were indeed successfully used to map eucalypt genomes (Byrne et al 1995;Gion et al 2000;Thamarus et al 2002) but did not provide the levels of polymorphism and throughput required for routine mapping in multiple pedigrees. It was only with the more recent development of large numbers of highly polymorphic microsatellite (or SSR) markers for Eucalyptus (Brondani et al 1998(Brondani et al , 2006Glaubitz et al 2001;Ottewell et al 2005;Steane et al 2001) that comparative mapping could be performed and linkage map synteny established across multiple pedigrees (Brondani et al 2006;Freeman et al 2006;Marques et al 2002;Hudson et al 2011;Kullan et al 2012). …”