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Dag Lindgren 2007 Much from DaDa work 2001-2003 and presentation by DaDa 2004 For more information look there Phenotype-progeny two stage is best for Scots pine! Danusevičius D & Lindgren D 2002. Two-stage selection strategies in tree breeding considering gain, diversity, time and cost. Forest Genetics. 9:145-157.
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Main findings Clonal test is superior (use for spruce)Clonal test is superior (use for spruce) Progeny testing not efficientProgeny testing not efficient For Pine, use 2 stage Pheno/ProgenyFor Pine, use 2 stage Pheno/Progeny Pine flowering not needed before age ~ 10 and even not until 25Pine flowering not needed before age ~ 10 and even not until 25
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Stage 2:.Sexual propagation of pre-selected individuals Reselection based on performance of the progeny Mating Testing of the progeny Stage 2:.Sexual propagation of pre-selected individuals Reselection based on performance of the progeny Mating Stage1: Phenotype test and pre-selection Testing of the progeny Phenotype/Progeny strategy
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Low budget favours Phenotype tests If budget is cut by half = simple Phenotype test 0.1 0.2 0.3 05101520 Budget per year and parent (%) Annual Group Merit, % Progeny Phenotype Pheno/Progeny
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Results: 2 stage is better 2 stage strategy was better under most reasonable values 2 stage strategy was better under most reasonable values Main scenario 0.0 0.3 0.6 0510152025 Annual Group Merit (%) Age of mating for progeny test (years) No marked loss would occur if mating is postponed to age 15No marked loss would occur if mating is postponed to age 15 Pheno/Progeny Progeny
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Optimum test time and size for pine (for one of the 50 full sib fams) Long-term breeding Stage 2. Progeny- test each of those 5 with 30 offspring Stage 1: Test 70 full-sibs Mating 2-4 years, at a high cost if feasible Lag- 3-4 years Cycle time~ 27 Gain=8 % GM/Y= 0,27% Select back the best of 5 when progeny- test age is 10 Select 5 at age 10
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Time schedule a bit short, select females at 12, top graft, cross (6 years) Select males at 15 and take home pollen for crosses
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 What if no pine flowers until age 25? Pheno/Progeny is still leading Phenotype with selection age of 25 is better Progeny is the last Budget cuts, high h 2 will favour Phenotype This means, singe stage Phenotype cycle time > 25 years and For the two-stage, pre-selection not at its optimum age (10 years) Main (h=0.1, budget=10), Flowers at age 25 0.179 0.135 0.140 0.00 0.05 0.10 0.15 0.20 Progeny Phenotype Pheno/ Progeny Annual Group Merit, %
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Conclusions Under all realistic values, Pheno/Progeny better than Progeny Sufficient flowering of pine at age 10 is desirable, but the disadvantage to wait until the age of 15 years was minor,
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Main findings- P ine (70) Use 2 stage Pheno/Progeny strategy Stage 1 Phenotype select at age 10 (15 only 3% GM lost) Stage 2 Progeny test select at ca 10 (30) With L(2001), Cycle time~ 27 Gain=8 % GM/Y= 0,27%
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Clonal- best; progeny- worst; Pine- phenotype pre-selection and progeny; flowers at age 15 Added advantages There will be tested genotypes available for orchards There will be tested genotypes available for orchards Different character mix may be used for phenotypes and progeny (a type of tandem selection) Different character mix may be used for phenotypes and progeny (a type of tandem selection) 2/3 of the breeding cycle will be used for testing instead of less than one half with progeny-testing 2/3 of the breeding cycle will be used for testing instead of less than one half with progeny-testing
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