Levels of outcrossing and contamination in two<i>Pinus sylvestris</i>L. seed orchards in Northern Sweden

El‐Kassaby, Yousry A.; Rudin, Dag; Yazdani, Reza

doi:10.1080/02827588909382544

Cited by 49 publications

(23 citation statements)

References 20 publications

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“…This would also offset due to pollen contamination from outside the seed orchard (El-Kassaby & Aakew 1991). Pollen contamination causes losses of genetic gain but enhances GD (El-Kassaby et al 1989;Torimaru et al 2009;Torimaru et al 2013). Loss of GD is inversely proportional to the group coancestry (Lindgren et al 1996) and the effective number (Kang & Lindgren 1998;Ertekin 2010).…”

Section: Discussionmentioning

confidence: 97%

Estimation of genetic gain and diversity under various genetic thinning scenarios in a breeding seed orchard ofQuercus acutissima

Lee

Han

et al. 2015

Scandinavian Journal of Forest Research

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Genetic gain and diversity were estimated based on three simulated thinning scenarios at various thinning intensities in a breeding seed orchard of Quercus acutissima. The seed orchard was composed of 32 families with 744 individual trees with volume at age 15. The three thinning scenarios were individual thinning (IT) which thinning was based on the individual performance, family thinning (FT) with the removal of inferior families regardless of individual performance, and family + within family thinning (FWF) with family first and then individual from inferior families. The genetic gain was estimated based on stem volume. Expected genetic gain (volume at age 15) under IT was higher than FT and FWF at all thinning intensities. The FWF provided higher genetic gain than FT but lower than IT. The FT gave the lowest genetic gain compared to the other thinning scenarios at all thinning intensities. The loss of gene diversity (GD), estimated by coancestry and family size, was higher under FWF and lower under FT at moderate thinning intensities. The study showed that genetic gain estimation and GD loss were inversely coupled. The IT gave highest genetic gain but lowest GD at the highest thinning intensity.

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Section: Discussionmentioning

confidence: 97%

Estimation of genetic gain and diversity under various genetic thinning scenarios in a breeding seed orchard ofQuercus acutissima

Lee

Han

et al. 2015

Scandinavian Journal of Forest Research

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“…Therefore, efforts should be taken with the selection of loci used (high polymorphism information content value (Botstein et al 1980)), minimal genotyping error and the use of appropriate pedigree reconstruction models. It should be stated also that the level of gene flow to the breeding arboreta is expected to increase the genotyping efforts and this increase is proportionate to pollen contamination (Friedman and Adams 1985;El-Kassaby et al 1989). However, if the realized selection differential between the breeding arboreta and outside pollen source is far from zero, it is expected that most of the extreme observations (top-ranking individuals) within a family are sired by selected parents (those with high general combining ability).…”

Section: Discussionmentioning

confidence: 97%

Breeding without breeding: minimum fingerprinting effort with respect to the effective population size

Lstibůrek

Ivanková

Kadlec

et al. 2011

Tree Genetics & Genomes

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We present a probabilistic model to minimize the fingerprinting effort associated with the implementation of the "breeding without breeding" scheme under partial pedigree reconstruction. Our approach is directed at achieving a declared target population's minimum effective population size (N e ), following the pedigree reconstruction and genotypic selection and is based on the graph theory algorithm. The primary advantage of the proposed method is to reduce the cost associated with fingerprinting before the implementation of the pedigree reconstruction for seed parentoffspring derived from breeding arboreta and production or natural populations. Stochastic simulation was Communicated by R. Burdon conducted to test the method's efficiency assuming a simple polygenic model and a single trait. Hypothetical population consisted of 30 parental trees that were paired at random (selfing excluded), resulting in 600 individuals (potential candidates for forwards selection). The male parentage was assumed initially unknown. The model was used to estimate the minimum genotyping sample size needed to reaching the prescribed N e . Results were compared with the known pedigree data. The model was successful in revealing the true relationship pattern over the whole range of N e . Two to three offspring entered genotyping to meet the N e = 2 while 41 to 43 were required to satisfy the N e = 14. Importantly, genetic gain was affected at the lower limits of the genotyping effort. Doubling the number of parents resulted in considerable reduction of the genotyping effort at higher N e values.

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“…In Finland and Sweden, several pine and spruce orchards were transferred up to 6-8 latitudinal degrees southwards (650-900 km) in the 1970s in order to accelerate flowering and increase seed-cone production and seed quality. However, transferring seed orchards does not completely eliminate pollen contamination (El-Kassaby et al 1989;Pulkkinen et al 1994). Supplemental pollination can reduce pollen contamination to a detectable extent, but is primarily used to introduce new parents into a seed orchard population at a reasonable cost (Eriksson and Wilhelmsson 1991) and thus to increase the genetic diversity in the orchard's crops (El-Kassaby and Ritland 1986;Eriksson et al 1994;Lai et al 2010).…”

Section: Communicated By Y Tsumuramentioning

confidence: 99%

Mating dynamics of Scots pine in isolation tents

Funda

Wennström

Almqvist

et al. 2016

Tree Genetics & Genomes

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Seed orchards are forest tree production populations for supplying the forest industry with consistent and abundant seed crops of superior genetic quality. However, genetic quality can be severely affected by non-random mating among parents and the occurrence of background pollination. This study analyzed mating structure and background pollination in six large isolation tents established in a clonal Scots pine seed orchard in northern Sweden. The isolation tents were intended to form a physical barrier against background pollen and induce earlier flowering relative to the surrounding trees. We scored flowering phenology inside and outside the tents and tracked airborne pollen density inside and outside the seed orchard in three consecutive pollination seasons. We genotyped 5683 offspring collected from the tents and open controls using nine microsatellite loci, and assigned paternity using simple exclusion method. We found that tent trees shed pollen and exhibited maximum female receptivity approximately 1 week earlier than trees in open control. The majority of matings in tents (78.3 %) occurred at distances within two trees apart (about 5 m). Selffertilization was relatively high (average 21.8 %) in tents without supplemental pollination (SP), but it was substantially reduced in tents with SP (average 7.7 %). Pollen contamination was low in open controls (4.8-7.1 %), and all tents remained entirely free of foreign pollen. Our study demonstrates that tent isolation is effective in blocking pollen immigration and in manipulating flowering phenology. When complimented with supplemental pollination, it could become a useful seed orchard management practice to optimize the gain and diversity of seed orchard crops.

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Levels of outcrossing and contamination in twoPinus sylvestrisL. seed orchards in Northern Sweden

Cited by 49 publications

References 20 publications

Estimation of genetic gain and diversity under various genetic thinning scenarios in a breeding seed orchard ofQuercus acutissima

Estimation of genetic gain and diversity under various genetic thinning scenarios in a breeding seed orchard ofQuercus acutissima

Breeding without breeding: minimum fingerprinting effort with respect to the effective population size

Mating dynamics of Scots pine in isolation tents

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