1 / 28

Principles of Grafting and Budding

Principles of Grafting and Budding. Chapter 11. Grafting & Budding Terms. Graft: Two living plants connected and growing as one. Scion: Dormant shoot, upper portion of graft. Stock: Lower portion of graft, root system. Grafting & Budding Terms.

federico-jara
Télécharger la présentation

Principles of Grafting and Budding

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Principles of Grafting and Budding Chapter 11

  2. Grafting & Budding Terms Graft: Two living plants connected and growing as one Scion: Dormant shoot, upper portion of graft Stock: Lower portion of graft, root system

  3. Grafting & Budding Terms Bud: Similar to graft, but scion is reduced to a single bud

  4. Grafting & Budding Terms Interstock: A middle or intermediate stem piece located between scion & stock

  5. Grafting & Budding Terms Vascular Cambium X P Vascular Cambium: Meristematic tissue between xylem & phloem

  6. Grafting and Budding • Perpetuate clones • Rootstock effects • Changing cultivars • Rapid maturity • Shortens juvenility • Used for breeding programs • Special growth forms • Damage repair • Studying viruses

  7. Seedling Rootstocks • Simple • Cheap • Disease free • Better root systems • Genetic variation

  8. Clonal Rootstocks • Source • Stool beds • Cuttings • Tissue Culture • Characteristics • Uniformity • Disease Resistance • Growth Habit • Flowering Habit • Scion rooting • Disease potential

  9. Rootstock benefits • Disease resistance • Soil tolerance • Size control • Fruit quality Interstock benefits • Overcome incompatibility • Add additional attributes • Dwarfing

  10. Topworking • Change cultivars • Add pollinators

  11. Topworking • Multiple varieties on one tree

  12. Formation of graft union • Line up vascular cambium • Wound healing response • Necrotic plate • Callus bridge formation • Cambium formation • Vascular tissue formation

  13. 1. Close Vascular Contact • 55-90F • Active cambium • High humidity • Pathogen free • Mechanical support • Cambium ‘matching’

  14. 2. Formation of Necrotic plate • Cells killed when cut is made

  15. 3. Callus Bridge Formation • Production & Interlocking of parenchyma • Comes from phloem and immature xylem • Stock produces most callus

  16. 4. New Cambium Formation • Adjacent callus differentiates to form cambium • Cambium forms across bridge of callus tissue

  17. 5. New Vascular Tissue (X&P) From New Cambium • Vascular system must be in place before bud break

  18. GRAFT FORMATION

  19. BUD FORMATION

  20. Factors of graft healing • Incompatibility • Species or variety (cultivar) • Temperature • Moisture • Oxygen • Growth status (active vs. dormant) • Technique or type of graft • Disease situation

  21. Polarity in grafting • Distal and Proximal ends • Reversed polarity works only for a limited time with grafts • Nurse-root grafting • Buds can be reversed • Can cause a wide crotch angle as it grows - strong

  22. Limits of grafting • Generally limited to dicots & gymnosperms • More closely related the better • Permanent grafts in monocots are not successful • Likely has a lot to do with cambium and vascular tissue production • Common between same species • Apple on apple • Harder between different Genera in same family • Tomato on potato (Solanaceae family, or Nightshade) • Rare between families

  23. Symptoms of Incompatibility • High failure rate • Yellow foliage, early defoliation • Premature death of scion • Differences in growth rate • Not always a sign of incompatibility • Can be differences in genetic potential for growth rate • Overgrowths • Breaks at graft union

  24. Types of Incompatibility • Localized • At site of graft contact • Translocated • Substances moved from the scion to rootstock or vice-versa • Virus present

  25. Incompatibility • Cause: Genetic • Mechanism (example theories): • Chemicals found in one partner may be toxic to the other (Cyanogenic glucoside) • Lignification of cell walls may be inhibited

  26. Effects of Rootstocks on the Scion • Size and growth habit • Fruiting • Size, quality, and maturity of fruit • Winter hardiness • Disease resistance • Timing of fruit maturity Effects of Scion on the Rootstock • Vigor • Cold-hardiness

  27. Effects of Interstock on Stock & Scion • Reduces stock and scion size • Direct effect, not indirect Mechanisms of effects (theory) • Translocation (stem) • Absorbing ability (root system) • Interaction of all parts

  28. Factors influencing growth of grafted plants • Nutrition • Translocation • Endogenous growth factors

More Related