Evolutionary history of tall fescue morphotypes inferred from molecular phylogenetics of the Lolium-Festucaspecies complex

BMC Evolutionary Biology

Research Article

Melanie L Hand¹  Noel OI Cogan²  John W Forster³  Alan V Stewart⁴ 

[1] Department of Primary Industries, Biosciences Research Division, Victorian AgriBiosciences Centre, 1 Park Drive, La Trobe University Research and Development Park, 3083, Bundoora, Victoria, Australia;La Trobe University, 3086, Bundoora, Victoria, Australia;Department of Primary Industries, Biosciences Research Division, Victorian AgriBiosciences Centre, 1 Park Drive, La Trobe University Research and Development Park, 3083, Bundoora, Victoria, Australia;Molecular Plant Breeding and Dairy Futures Cooperative Research Centres, Australia;Department of Primary Industries, Biosciences Research Division, Victorian AgriBiosciences Centre, 1 Park Drive, La Trobe University Research and Development Park, 3083, Bundoora, Victoria, Australia;Molecular Plant Breeding and Dairy Futures Cooperative Research Centres, Australia;La Trobe University, 3086, Bundoora, Victoria, Australia;PGG Wrightson Seeds, P.O. Box 175, 7640, LincolnCanterbury, New Zealand;

关键词: Internal Transcribe Spacer;    Tall Fescue;    Perennial Ryegrass;    Diploid Progenitor;    Parsimony Informative Site;   

DOI  :  10.1186/1471-2148-10-303

 received in 2010-06-02, accepted in 2010-10-12,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events.ResultsPutative homoeologous sequences from both nuclear genes were obtained from each polyploid species and compared to counterparts from 15 diploid taxa. Phylogenetic reconstruction confirmed F. pratensis and F. arundinacea var. glaucescens as probable progenitors to Continental tall fescue, and these species are also likely to be ancestral to the rhizomatous morphotype. However, these two morphotypes are sufficiently distinct to be located in separate clades based on the ITS-derived data set. All four of the generated data sets suggest independent evolution of the Mediterranean and Continental morphotypes, with minimal affinity between cognate sequence haplotypes. No obvious candidate progenitor species for Mediterranean tall fescues were identified, and only two putative sub-genome-specific haplotypes were identified for this morphotype.ConclusionsThis study describes the first phylogenetic analysis of the Festuca genus to include representatives of each tall fescue morphotype, and to use low copy nuclear gene-derived sequences to identify putative progenitors of the polyploid species. The demonstration of distinct tall fescue lineages has implications for both taxonomy and molecular breeding strategies, and may facilitate the generation of morphotype and/or sub-genome-specific molecular markers.

【 授权许可】

Unknown   
© Hand et al; licensee BioMed Central Ltd. 2010. 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.