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Is linear deployment of clones optimal under different clonal outcrossing contributions in seed orchards

Author:
Prescher, F., Lindgren, D., El-Kassaby, Y. A.
Source:
Tree genetics & genomes 2006 v.2 no.1 pp. 25-29
ISSN:
1614-2942
Subject:
Picea abies, breeding value, clones, genetic improvement, genotype, germ cells, outcrossing, seed orchards
Abstract:
Self-pollen seldom results in vital genotypes and can thus be regarded as unimportant. Large-sized clones (clones with many ramets) are more exposed to self-pollen and spread more self-pollen and thus contribute relatively less than small-sized clones. The size of clones required to maximize genetic gain at given diversity, considering that only outcrossing contributes to successful gametes, was derived for tested clones intended to establish a Norway spruce (Picea abies) seed orchard. The derived optimal deployment was compared with linear deployment according to Lindgren and Matheson (Silvae Genet 35:173-177, 1986), where the size of a clone is deployed proportional to its breeding value. The study covered a range of effective numbers between 5 and 50. The results suggest that linear deployment is a good approximation to optimal deployment when only outcrossing is considered. The difference between the two strategies is decreased by increasing clone number and is negligible except at low effective numbers.
Agid:
2070630