Contrasting relationships between the diversity of candidate genes and variation of bud burst in natural and segregating populations of European oaks

doi:doi:10.1038/hdy.2009.134

Heredity advance online publication 7 October 2009; doi: 10.1038/hdy.2009.134

Contrasting relationships between the diversity of candidate genes and variation of bud burst in natural and segregating populations of European oaks

J Derory^1,2, C Scotti-Saintagne^1,2,4, E Bertocchi^1,2, L Le Dantec³, N Graignic^1,2, A Jauffres^1,2, M Casasoli^1,2, E Chancerel^1,2, C Bodénès^1,2, F Alberto^1,2 and A Kremer^1,2

¹INRA, UMR1202 BIOGECO, Cestas, France
²Université de Bordeaux, UMR1202 BIOGECO, Cestas, France
³INRA, UPR419, Unité de Recherche sur les Espèces Fruitières, Villenave d'Ornon, France
⁴INRA, UMR745 ECOFOG, Kourou, French Guiana

Correspondence: Dr A Kremer, BIOGECO, INRA, UMR BIOGECO 1202, 69, rte d'Arcachon, Cestas, F-33610, France. E-mail: antoine.kremer@pierroton.inra.fr

Received 2 March 2009; Revised 10 August 2009; Accepted 17 August 2009; Published online 7 October 2009.

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Abstract

Nucleotide diversity was assessed within nine candidate genes (CGs) (in total 4.6 kb) for the time of bud burst in nine sessile oak (Quercus petraea) populations distributed in central and northern Europe. The sampled populations were selected on the basis of their contrasting times of bud burst observed in common garden experiments (provenance tests). The CGs were selected according to their expression profiles during the transition from quiescent to developing buds and/or their functional role in model plants. The overall nucleotide diversity was large (_tot=6.15 $times$ 10^-3; _silent=11.2 $times$ 10^-3), but population differentiation was not larger than for microsatellites. No outlier single-nucleotide polymorphism (SNP) departing from neutral expectation was found among the total of 125 SNPs. These results contrasted markedly with the significant associations that were observed between the CGs and bud burst in segregating populations. Quantitative trait loci (QTLs) for bud burst were identified for 13 year midast site seasonal observations in a cloned mapping pedigree. Nineteen QTLs were detected, and QTLs located on linkage groups 2, 5 and 9 contributed repeatedly to more than 12% of the phenotypic variation of the trait. Eight genes were polymorphic in the two parents of the pedigree and could be mapped on the existing genetic map. Five of them located within the confidence intervals of QTLs for bud burst. Interestingly, four of them located within the three QTLs exhibiting the largest contributions to bud burst.