Development of Trifolium occidentale as a Plant Model System for Perennial Clonal Species
Trifolium occidentale D.E. Coombe is a diploid, clonal perennial clover that is very closely related to white clover (T. repens L.). It has been previously reported to be self-pollinating and lacking in genetic diversity. However, new collections, especially in Spain and Portugal, have revealed that cross-pollinating populations with substantial genetic diversity do exist. This has led to T. occidentale being investigated as a potential genetic model species to facilitate the application of genomic methods for the improvement of white clover. Investigations have shown that T. occidentale has many attributes that make it suitable as a genetic model for white clover. It forms hybrids with white clover and the chromosomes of the two species pair and recombine at meiosis. Phylogenetic research shows that it is a very close relative, and probably an ancestor, of white clover. A framework linkage map based on SSR markers has shown it to be highly syntenic with white clover. A protocol for efficient transformation has been developed. An effective EMS mutagenesis method has been demonstrated by the induction of a high frequency of condensed tannin negative mutants. The clonal nature of T. occidentale is not shared by other dicotyledonous model species. It may, therefore, be useful for the genomic characterisation of traits associated with clonal growth and perenniality in this wider class of plants.
KeywordsCondensed Tannin White Clover Flower Head Ammonium Glufosinate Substantial Genetic Diversity
Unable to display preview. Download preview PDF.
- Caradus JR, Woodfield DR (1997) World checklist of white clover varieties II. N Z J Agric Res 40:115–206Google Scholar
- Chen C-C, Gibson PB (1970) Meiosis in two species of Trifolium. and their hybrids Crop Sci 10:188–189Google Scholar
- Coombe DE (1961) Trifolium occidentale, a new species related to T. repens L. Watsonia5:68–87Google Scholar
- Géhu J-M (1972) Trifolium occidentale. D.E.Coombe espece noevelle pour le littoral du nord du Portugal Agron Lusitana 34:197–204Google Scholar
- Gibson PB, Beinhart G (1969) Hybridization of Trifolium occidentale. with two other species of clover J Hered 60:93–96Google Scholar
- Kendall WA (1966) Factors affecting foams with forage legumes. Crop Sci 6:487–489Google Scholar
- Preston CD (1980) Trifolium occidentale. D.E. Coombe, new to Ireland. Ir Nat J 20:37–40Google Scholar
- Rivas-Martínez S (1976) Notes systématiques, chorologiques et écologiques sur des plantes d’Espagne, 1. Candollea 31:111–117Google Scholar
- Williams WM, Verry IM, Ellison NW (2006) A phylogenetic approach to germplasm use in clover breeding. In: Mercer CF (ed) Breeding for success: diversity in action. Proc 13th Australasian Plant Breeding Conference, Christchurch, New Zealand, 18–21 April 2006, pp. 966–971Google Scholar
- Zohary M, Heller D (1984) The genus Trifolium. The Israel Academy of Sciences and Humanities, JerusalemGoogle Scholar