Evaluating the utility of Arabidopsis thaliana as a model for understanding heterosis in hybrid crops
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Despite the phenomenon of heterosis having been used to improve crop productivity for almost a century, there is little understanding of the molecular mechanisms involved. Heterosis has been described recently in the widely used plant model Arabidopsis thaliana. To assess the opportunity afforded by this system, we have developed, through pollination to a male sterile female parent (Ler ms1), a range of hybrids of A. thaliana accessions. We tested this method of hybrid production in A. thaliana by comparing seed produced by natural pollination and hand pollination of emasculated plants. Our results demonstrate that using male sterile lines, which more closely represent methods used for hybrid crop production, circumvents the problems associated with the analysis of hybrids produced from emasculated plants. We identified hybrid combinations exhibiting mid-parent heterosis for vegetative fresh weight ranging from −9 to 103% and characterised heterosis in the reciprocal hybrids of one strongly heterotic combination. We found no evidence of a relationship between the extent of genetic relatedness of A. thaliana accessions and the strength of heterosis exhibited by their hybrids.
KeywordsHeterosis Hybrid vigour Arabidopsis Seed size Reciprocal effects Genetic distance
This work was supported by the John Innes Centre Competitive Support Grant and a quota PhD studentship to D.S. from the UK Biotechnology and Biological Sciences Research Council.
- Duvick DN (1999) Heterosis: feeding people and protecting natural resources. In: Coors JG, Pandey S (eds) The genetics and exploitation of heterosis in crops. ASA, CSSA, and SSSA, Madison, WI, pp 19–29Google Scholar
- El Asmi H (1974) Further analysis of heterosis and its expression for the rosette diameter length in Arabidopsis thaliana. Arabidopsis Inf Serv 12:24Google Scholar
- Griffing B, Langridge J (1963) Phenotypic stability of growth in self-fertilised species. Arabidopsis thaliana. In: Hanson WD, Robinson HF (eds) Statistical genetics and plant breeding. National Research Council, Washington, pp 368–394Google Scholar
- Melchinger AE, Lee M, Lamkey KR, Hallauer AR, Woodman WL (1990) Genetic diversity for restriction fragment length polymorphisms and heterosis for two diallel sets of maize inbreds. TAG Theor Appl Genet 80:488–496Google Scholar
- Srivastava HK (2002) Mitochondrial complementation and hybrid vigour. Indian J Genet Plant Breed 32:215–228Google Scholar
- The Arabidopsis Genome Initiative (2000) Analysis of the genome sequence of the flowering plant Arabidopsis thaliana. Nature 408:796–815Google Scholar