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Picea abies breeding in Sweden is based on clone testing

100%

Lindgren D.

Dendrobiology

2009

tom 61 Supplement

In the last decades, clone testing has become an important component of the long-term breeding and seed orchards for Norway spruce in Sweden. For more than three decades, considerable resources have been spent on testing clones intended for clonal forestry, but the Swedish forestry never saw it worth to pay the added cost involved in the added gain. The efforts, however, resulted in many clone trials and developments in the technique for clone production and propagation. Theoretically, clone testing is faster and cheaper than progeny testing and more reliable than selecting individuals forwards. Nowadays, the main line in long-term breeding is to make crosses between the best trees and test-cloned full-sibs as a recruitment population for long-term breeding and seed orchards. Since controlled crosses are a bottleneck for long-term breeding, a possibility is to rely on wind pollination (Breeding Without Breeding; BWB) in trials for testing clones. The seed parent is known, and that the pollen parent is a desirable genotype can be checked by molecular markers. BWB has the potential to eliminate the waiting time between selection and recombination, which is particularly important in a late and irregularly flowering species such as Norway spruce. Clone testing ensures that the breeding values are known from the same tests as those used for BWB. Another option for BWB is to place in seed orchards a few ramets of clones belonging to the breeding population, but normally not deserving such a use, with the hope that their presence will make it possible to rely on wind pollination to recombine the whole breeding population.

Strategy for long-term breeding of Picea abies in Lithuania: short overview

100%

Danusevicius D.

Dendrobiology

2009

tom 61 Supplement

This paper presents the newly suggested long-term breeding strategy for Norway spruce in Lithuania to share with the optimisation approach, which may be useful in synchronising the long-term breeding and gene conservation plans in neighbouring regions. The breeding programme in Lithuania is at a stage where the long-term plans need to be developed. Our strategy is to proceed with a closed-nucleus breeding population which is structured into subpopulations according to adaptation zones (4-5 subpopulations). The size of each subpopulation is 50 unrelated and progeny-tested individuals. The breeding cycle consists of double- pair mating and a balanced within-family selection forward. The candidates will be clone-tested. Advanced genotypes will be selected into an advanced nucleus; an isolated foreign breeding population is planned. Positive assortative mating is used for deployment. An experimental "shuttle-breeding" strategy may be tested: selection with avery high intensity, controlled crosses, nursery tests for vigour and growth rhythm, cloning by hedges into short-rotation clonal plantations.

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2 Dendrobiology

1 Danusevicius D.

1 Lindgren D.

2 2009

Wyniki wyszukiwania

Picea abies breeding in Sweden is based on clone testing

Strategy for long-term breeding of Picea abies in Lithuania: short overview