Association study between the gibberellic acid insensitive gene and leaf length in a Lolium perenne L. synthetic variety

BMC Plant Biology

Research Article

Christian Huyghe¹  Jérôme Auzanneau¹  Bernadette Julier¹  Philippe Barre¹  Abraham J Escobar-Gutiérrez¹  François Gastal¹ 

[1] INRA, UR4, Unité de Recherche Pluridisciplinaire Prairies et Plantes Fourragères, Le Chêne, RD 150, 86600, Lusignan, France;

关键词: Quantitative Trait Locus;    Core Collection;    Leaf Length;    Perennial Ryegrass;    Leaf Elongation;   

DOI  :  10.1186/1471-2229-11-183

 received in 2011-07-07, accepted in 2011-12-28,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundAssociation studies are of great interest to identify genes explaining trait variation since they deal with more than just a few alleles like classical QTL analyses. They are usually performed using collections representing a wide range of variability but which could present a genetic substructure. The aim of this paper is to demonstrate that association studies can be performed using synthetic varieties obtained after several panmictic generations. This demonstration is based on an example of association between the gibberellic acid insensitive gene (GAI) polymorphism and leaf length polymorphism in 'Herbie', a synthetic variety of perennial ryegrass.MethodsLeaf growth parameters, consisted of leaf length, maximum leaf elongation rate (LERmax) and leaf elongation duration (LED), were evaluated in spring and autumn on 216 plants of Herbie with three replicates. For each plant, a sequence of 370 bp in GAI was analysed for polymorphism.ResultsGenetic effect was highly significant for all traits. Broad sense heritabilities were higher for leaf length and LERmax with about 0.7 in each period and 0.5 considering both periods than for LED with about 0.4 in each period and 0.3 considering both periods. GAI was highly polymorphic with an average of 12 bp between two consecutive SNPs and 39 haplotypes in which 9 were more frequent. Linkage disequilibrium declined rapidly with distance with r 2 values lower than 0.2 beyond 150 bp. Sequence polymorphism of GAI explained 8-14% of leaf growth parameter variation. A single SNP explained 4% of the phenotypic variance of leaf length in both periods which represents a difference of 33 mm on an average of 300 mm.ConclusionsSynthetic varieties in which linkage disequilibrium declines rapidly with distance are suitable for association studies using the "candidate gene" approach. GAI polymorphism was found to be associated with leaf length polymorphism which was more correlated to LERmax than to LED in Herbie. It is a good candidate to explain leaf length variation in other plant material.

【 授权许可】

Unknown   
© Auzanneau et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.