Choice of Population Size and Use of Variation Between Replicate Populations in Plant Breeding Selection Programs1
- L. H. Baker and
- R. N. Curnow2
Some factors which influence the choice of population size in selection aimed at improving composite populations of maize as sources of inbred lines are considered. The consequences of different effective population sizes on progress from selection within a population with a specific genetic model are examined, using a new mathematical approach described by Curnow and Baker (1968) [but see correction and Curnow and Baker (1969) and later errata notice]. The results obtained suggest that reasonably rapid progress from selection can be expected with small effective population sizes. Substantial added progress may be obtained if selection can be practiced within each of a number of replicate lines developed out of the same original population, followed by selection of the best replicate lines.
The results obtained also suggest that the selected lines should be tested in all possible combinations to identify outstanding lines which can then serve as sources of new inbred lines or as foundation material for new crosses in which selection can then be practiced.
The effect of departures from the assumed genetic model are discussed. However, the work reported reflects results expected with a specific genetic model. The most important finding is that conditions can exist where recommendations on population size, at present basic in the planning of a selection program, should be reconsidered.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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