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

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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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Nội dung Text: Báo cáo nghiên cứu nông nghiệp " Forest Tree Seed –definitions and concepts "

Forest Tree Seed – definitions and concepts 1
Concepts 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 17
Concepts to define – 2 7. Orthodox Seed 8. Unorthodox Seed 9. 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