Softwood and Semihardwood Cuttings and Micro propagation

1. Softwood and Semihardwood Cuttings and Micro propagation Unit 7

2. Objectives • Select plants suitable for propagating by use of cuttings and determine if the maturity of wood is correct for optimum rooting • Write a brief description of the tissue culture procedure

3. Asexual Reproduction • Required for plants that are sterile (do not produce seeds) • Cuttings: - most commonly used method • May be taken from a leaf, bud, stem or root • May be taken when tissue is soft and tender (softwood cutting) • Or, when plant tissue is hardened (hardwood cuttings)

4. Rooting • To root, cuttings require basically the same conditions that seeds need to germinate • Moisture, oxygen, and warmth • Light is also essential for photosynthesis • Root formation is stimulated because of the interruption of downward movement of carbohydrates, hormones and other materials from leaves • Additional rooting hormones are used to aid in root formation

5. Softwood and Semihardwood Stem Cuttings • Taken after the present season’s growth has a least partially matured or hardened • Plant should have made at least 2-6 inches of growth • Plant should have adequate moisture • Early morning is the best time to take a cutting because shoots will have more moisture

6. Taking the cutting • Immediately after taking the cutting, place it in a bucket of water • Prepare a label w/ the variety name and date • The plant must have leaves at the time of cutting • Help to know the top of the cutting (leaves point upward) • Cut bottom at 45 degree angle and top at 90 degrees

7. Preparing the container • Should be at least 4 inches deep • Needs holes in the bottom for drainage • Medium must be sterile to prevent rotting

8. Treating w/ Hormones • Follow directions on the label • Chemicals that help rootings grow roots faster • Hormone should contain a fungicide to prevent rotting • Immediately place cutting in medium to ½ its length but not more than 2 inches • Press medium around cutting firmly • Do not water when using a powdered hormone

9. Controlling the Atmosphere • Keep relative humidity around 100% • No roots to take in water • Place out of direct sunlight • Light increases Carbohydrates (help w/ root growth) • Direct Sunlight causes too much heat • Keep temperature at 65 – 70 degrees

10. Rooting • When roots develop a root ball about 2-3 inches across it is time to harden them off for transplanting • Hardening off should be done slowly over a period of 7 – 14 days • Plants must adapt to a new, drier atmosphere • Keep medium moist but not wet • After hardening off, cuttings are ready to be lined out – planted outside in; the nursery row under shade or sprinklers… or transplanted

11. Micropropagation – Tissue Culture • Asexual method using sterilized terminal shoots or leaf buds placed on a sterile agar gel or other nutrient-growing medium • Buds or stem tips and medium are placed inside a test tube or small jar and kept sealed • As sprouts grow large enough to be moved, they are pulled off and placed in a new medium to grow roots • When roots develop the container may be opened allowing the plants to harden off • Plants can then be transplanted and treated the same as seedling transplants

12. Other types of Softwood cuttings • Leaf Cuttings • Leaf-Bud Cuttings • Mallet Cutting • Root Cuttings

13. Objectives • Select plants suitable for propagating by use of cuttings and determine if the maturity of wood is correct for optimum rooting • Write a brief description of the tissue culture procedure