Modern Advances in Tree Breeding
Traditional tree improvement programs are long-term endeavours requiring extensive resources. They require establishing mating designs, installing progeny tests on multiple sites to evaluate parents and their offspring over large geographic areas, monitor
- PDF / 473,108 Bytes
- 19 Pages / 439.37 x 666.142 pts Page_size
- 73 Downloads / 197 Views
Abstract Traditional tree improvement programs are long-term endeavours requiring extensive resources. They require establishing mating designs, installing progeny tests on multiple sites to evaluate parents and their offspring over large geographic areas, monitoring those tests over extended periods of time, and eventual analysis of measurements to assess economic traits. Most tree breeding programs follow the classical recurrent selection scheme, resulting in the generation of multiple breeding and production populations. This process, while successful in attaining appreciable gains, remained static for a long time. The availability of plentiful, reliable, and most of all increasingly affordable genetic markers brought about drastic changes to present-day breeding methods. In this chapter, we focus on four significant genetic marker-dependent approaches with significant potential to directly or indirectly change contemporary tree breeding methods. These include pedigree reconstruction, pedigree-free models, association genetics, and genomic selection.
1 Introduction Tree breeding programs are resource- and time-dependent endeavours. The selection and testing phases are often conducted over vast geographic areas with large trials, requiring frequent and long-time monitoring and assessment. The lowest-intensity
Y.A. El-Kassaby (*) Department of Forest Sciences, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada e-mail: [email protected] F. Isik • R.W. Whetten Department of Forestry and Environmental Resources, North Carolina State University, Campus Box 8002, Raleigh, NC 27695, USA e-mail: [email protected]; [email protected]; [email protected] T. Fenning (ed.), Challenges and Opportunities for the World’s Forests in the 21st Century, Forestry Sciences 81, DOI 10.1007/978-94-007-7076-8_18, © Springer Science+Business Media Dordrecht 2014
441
442
Y.A. El-Kassaby et al.
approach to tree improvement is a reciprocal transplanting-like approach known as provenance testing (Callaham 1964) for the identification of superior seed sources for reforestation. Provenance testing allowed evaluating several seed sources originating from multiple locations within the species’ natural range through their fieldtesting over potential target planting areas. This process aided in identifying superior seed sources and their adaptability for the safe transfer of their seed to the new planting sites (Rehfeldt 1983). Provenance testing focused on acquiring precise knowledge of the seed sources and their performance over testing sites (Konig 2005). This process is a simple population improvement method, as the pedigree or genealogy of the tested material is often unknown. The main achievement of provenance testing is the delineation of areas for safe seed transfer, known as seed zones (Campbell 1986). The first and simplest pedigree-known testing utilized wind-pollinated/open- pollinated families (also known as half-sib families because their offspring share the seed donors’ genotype). Win
Data Loading...
