Báo cáo nghiên cứu nông nghiệp Forest Tree Seed –definitions and concepts

Provenance• Place where seed was collected• Refers to natural forests, not plantations• Provenance boundaries not always well defined• Provenances may have different genetic adaptation. Subdivision of a species, with genetically similar individuals.• Sometimes synonymous with provenance.• Races separated using observed differences.• For example, wood basic density, bark thickness, and flowering patterns have been used to define E. globulusraces
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Báo cáo nghiên cứu nông nghiệp " Forest Tree Seed –definitions and concepts " Forest Tree Seed– definitions and concepts 1Concepts to define – 1 1. Provenance 2. Race 3. Land Race 4. Family 5. Seedlot 6. Genetic gain 2 1. Provenance• Place where seed was collected• Refers to natural forests, not plantations• Provenance boundaries not always well defined• Provenances may have different genetic adaptation 3 1. Provenance• Example – E. camaldulensis 4 2. Race• Subdivision of a species, with genetically similar individuals.• Sometimes synonymous with provenance.• Races separated using observed differences.• For example, wood basic density, bark thickness, and flowering patterns have been used to define E. globulus races 5 3. Land Race• Introduced trees that are adapted to an environment after several generations. 6 3. Land Race• Introduced trees that are adapted to an environment after several generations.• Advantage: Selection may help land races adapt to a new environment. 7 3. Land Race• Introduced trees that are adapted to an environment after several generations.• Advantage: Natural selection helps land races adapt to a new environment.• Disadvantages: May not be from the best natural provenances, and/or may come from very small genetic base. 8 4. Family• Individuals with parents in common. 9 4. Family• Individuals with parents in common.• Half-sib family: One parent in common (mother for trees). Father is unknown, through natural pollination. 10 4. Family• Individuals with parents in common.• Half-sib family: One parent in common (mother for trees). Father is unknown, through natural pollination.• Full-sib family: Both parents in common. Generated by controlled (artificial) pollination. 11 4. Family• Individuals with parents in common.• Half-sib family: One parent in common (mother for trees). Father is unknown, through natural pollination.• Full-sib family: Both parents in common. Generated by controlled (artificial) pollination.• Progeny: Trees produced from seed of a known parent. 12 4. Family• SINGLE TREE COLLECTION seed collected from 1 mother tree (i.e. progeny will be a half-sib family) 13 4. Family• SINGLE TREE COLLECTION seed collected from 1 mother tree (i.e. progeny will be a half-sib family)• Half-sib family: One parent in common (mother for trees). Father is unknown, through natural pollination.• Progeny: Trees produced from seed of a known parent. 14 5. Seedlot• Collection from a stand in one location at ONE POINT IN TIME• Reference number – links to seed collection information, storage, dispatch etc.• Can be a “bulk” or a group of single tree collections from the 1 stand, or both(“Bulk” = seed from >1 parent) 15 5. Seedlot code• For a bulk seedlot to be REPRESENTATIVE of a provenance, should have 10-15 parents (or more) equally represented 16 6. Genetic gain Gain ƒ ( i h2 σp )Where: σp → variability h2 → genetic control → selection intensity i 17Concepts to define – 27. Orthodox Seed8. Unorthodox Seed9. Recalcitrant Seed 18 7. Orthodox Seed• Seeds can be dried down to low moisture content (5%) & successfully stored at low temperatures for long periods 19 8. Unorthodox Seed• Seed that is not orthordox can not be dried down to low moisture content (5%) can not be successfully stored at low temperatures for long periods 20