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Seed orchards - genetic considerations on function, management and seed procurement

Prescher, Finnvid (2007). Seed orchards - genetic considerations on function, management and seed procurement. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2007:75
ISBN 978-91-576-7374-9
[Doctoral thesis]



Seed orchards are a cost-efficient way to increase future forest production. This thesis summarizes and discusses the results of eleven studies developing models and evaluating real seed orchard data to improve seed orchard management in Pinus sylvestris L. and Picea abies (L.) Karst. When establishing a new seed orchard, not much emphasis should be put on selecting clones with high fertility, since variation in female fertility was found to be rather low and difficult to forecast. For considering active life time of a seed orchard, the possible genetic improvement is an important factor, but there are other factors such as seed production and seed harvest cost that have to be considered as well. The age at which replacement is justified seems to be 30 years for Pinus sylvestris, and 40 years for Picea abies. The age becomes shorter if forest owners are willing to pay more for genetically better reproductive material. It is suggested that advanced-generation seed orchards in Sweden should contain 20-25 tested clones, with ramets deployed linearly with respect to breeding value, for an effective number of 15-18 clones. Even considering the complication that outcrossing pollen is more effective than selfing; the linear deployment concept is close to optimal. The linear deployment algorithm was applied to genetic thinning of two orchards, combining desires for high gain and conservation of gene diversity. The harvesting of cones can often be started as soon as significant amounts of cones develop (typically by age eight in Pinus sylvestris), but if contaminating pollen changes the adaptability of the harvested seed, harvest may be postponed until levels of orchard pollen increase or the use of the seeds modified. Around one quarter of the seed production occurred in the top level of the crown, half in the middle, and one quarter in the bottom. A yield of 9 kg seed per hectare is possible in Pinus sylvestris seed orchards. The cone harvest is a dominating cost which has consequences for management, e.g., orchards should be pruned in order to reduce tree height and thus lower harvesting costs.

Authors/Creators:Prescher, Finnvid
Title:Seed orchards - genetic considerations on function, management and seed procurement
Year of publishing :2007
Number of Pages:49
ALLI. Prescher, F., Lindgren, D., Almqvist, C., Kroon, J., Lestander, T. & Mullin, T. 2007. Female fertility variation in mature Pinus sylvestris clonal seed orchards. Scandinavian Journal of Forest Research 22:00-00 (in press). II. El-Kassaby, Y.A., Prescher, F. & Lindgren, D. 2007. Advanced generation seed orchards as affected by breeding advance, timing of seed crop, and cost components with special reference to Scots pine in Sweden. Scandinavian Journal of Forest Research 22:88-98. III. Moriguchi, Y, Prescher, F. & Lindgren, D. Optimal lifetime for Swedish Picea abies seed orchards. (Submitted). IV. Lindgren, D. & Prescher, F. 2005. Optimal clone number for seed orchards with tested clones. Silvae Genetica 54(2):80-92. V. Lindgren, D., Tellalov, Y. & Prescher, F. 2007. Seed set for Scots pine grafts are difficult to predict. In Isik, F. (ed) Low input breeding and conservation of forest genetic resources. Proceedings of the IUFRO Division 2 Joint Conference. Antalya, Turkey, 9-13 October 2006. pp 139-141. VI. Kroon, J., Prescher, F., Wennström, U. & Lindgren, D. Cone set over time for different clones in a seed orchard. (Manuscript). VII. Prescher, F., Lindgren, D. & El-Kassaby, Y. 2006. Is linear deployment of clones optimal under different clonal outcrossing contributions in seed orchards? Tree Genetics and Genomes 2:25-29. VIII. Prescher, F., Lindgren, D. & Karlsson, B. 2007. Genetic thinning of clonal seed orchards using linear deployment may improve both gain and diversity. Forest Ecology and Management (in press). IX. Prescher, F, Lindgren, D., Wennström, U., Almqvist, C., Ruotsalainen, S. & Kroon, J. 2005. Seed production in Scots pine seed orchards. In Fedorkov, A. (ed) Status, monitoring and targets for breeding programs. Proceedings of the meeting of Nordic forest tree breeders and forest geneticists, Syktyvkar. pp. 65-71. X. Bilir, N., Prescher, F., Ayan, S. & Lindgren, D. 2006. Growth characters and number of strobili in clonal seed orchards of Pinus sylvestris. Euphytica 152:293-301. XI. Bilir, N., Prescher, F., Lindgren, D. & Kroon, J. Variation in seed related characters in clonal seed orchards of Pinus sylvestris. (Manuscript).
Place of Publication:Umeå
ISBN for printed version:978-91-576-7374-9
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:pinus sylvestris, picea abies, seed stands, seed production, management, clones, cones, seed characteristics
Keywords:Seed orchard, fertility variation, clone number, linear deployment, rotation age, orchard management, cone harvest, seed characters
Permanent URL:
ID Code:1517
Department:(S) > Dept. of Forest Genetics and Plant Physiology
Deposited By: Finnvid Prescher
Deposited On:23 Aug 2007 00:00
Metadata Last Modified:02 Dec 2014 10:12

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