Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Abbreviations
- 1 Grassland improvement and environmental protection
- 2 The plant genetic base for grassland improvement
- 3 The nitrogen economy of grasslands
- 4 Growth and defoliation
- 5 Grassland ecology
- 6 Grazing management
- 7 Innovation, optimization and the realization of change
- Appendix The International Grassland Congresses
- References
- Index
2 - The plant genetic base for grassland improvement
Published online by Cambridge University Press: 19 September 2009
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Abbreviations
- 1 Grassland improvement and environmental protection
- 2 The plant genetic base for grassland improvement
- 3 The nitrogen economy of grasslands
- 4 Growth and defoliation
- 5 Grassland ecology
- 6 Grazing management
- 7 Innovation, optimization and the realization of change
- Appendix The International Grassland Congresses
- References
- Index
Summary
Introduction
The recognition of elite plant germplasm and the constitution of new gene combinations through hybridization have long been fundamental to grassland improvement; simplistically this seeks to optimize the conversion of carbon dioxide, water and minerals to supply digestible herbage acceptable to livestock and to protect environmental resources from degradation.
By the time of the IV International Grassland Congress in 1937 bred varieties from the Welsh Plant Breeding Station at Aberystwyth, such as the late flowering, leafy Lolium perenne cv. S23, were well entrenched in agriculture, as were varieties from Sweden, Denmark and other European countries (Osvald, 1937). In Sweden the identification of ecotypes and selection procedures were being applied to legumes such as Trifolium pratense, T. hybridum and T. repens, especially with respect to winter hardiness. The perennial cry of the seed grower that selection for leafiness led to poor synchrony of flowering and late maturing crops (Evans, 1937) would be reiterated for the next 60 years. Genetic studies with T. pratense were sufficiently advanced to describe the location of genes on chromosomes, the inheritance of chlorophyll deficiency, and the occurrence of both self- and cross-incompatibility (Williams, 1937). From the USA Cardon (1937) reported active breeding programmes and studies to define breeding objectives; the impact of bred varieties had yet to emerge.
- Type
- Chapter
- Information
- The Evolving Science of Grassland Improvement , pp. 29 - 73Publisher: Cambridge University PressPrint publication year: 1997