Transcript plant_prop
Plant Propagation 18.00: Apply different methods of plant propagation as related to horticultural plant production Propagation • The multiplication of a kind or species. • Reproduction of a species. Sexual Propagation • Propagation from seeds. • Pollen is transferred from the anther to the stigma. • Fertilization occurs and seeds are produced. Germination Rates • Percent of seeds that sprout – 75 out of 100=75% • Rate is affected by seed viability, temperature and moisture. • Rates vary depending on plant and quality of seed. Seeds • Plant depth depends on the size of seeds – larger seeds are planted deeper – water small seeds from bottom by soaking Embryo Seed Coat Endosperm Seedlings (small plants) • Transplant when first true leaves appear • Reduce humidity and water and make environment more like outside to “harden off” plants Seeds to Seedlings Advantages of Sexual Reproduction • Fast way to get many plants • Easy to do • Economical Disadvantages of Sexual Reproduction • Some plants, especially hybrids, do not reproduce true to parents • Some plants are difficult to propagate from seeds Asexual Propagation Foldable • Asexual Reproduction • Rootings from Cuttings • Stem Cuttings • Leaf Cuttings • Layering • Division or Separation • Grafting • On the back: Biotechnology Asexual Reproduction • Uses growing plant parts other than seeds • Types of asexual reproduction: – cuttings – layering – division or separation – budding – grafting – tissue culture Rooting from Cuttings • Rooting media should be about 4 inches deep • Best time of day is early mornings because plants have more moisture • Types of cuttings: – stem – leaf – root Stem Cuttings • Using a small piece of stem to reproduce plants • using hormones and dipping in fungicides help speed up rooting Leaf cuttings • Using small pieces of leaves to reproduce new plants • from herbaceous plants • vein must be cut Stem Cuttings-Step 1 Gather all materials needed Stem Cuttings-Step 2 Cut 3 to 4 inch shoot from stem tip Stem Cuttings-Step 3 Remove lower leaves from the shoot Stem Cuttings-Step 4 Dip cut surface in rooting hormone Stem Cuttings-Step 5 Thoroughly moisten rooting medium Stem Cuttings-Step 6 Stick one or more cuttings in rooting media Stem Cuttings-Step 7 Cover with plastic wrap or place on a mist bench in a warm area away from direct sunlight. Stem Cuttings-Step 8 Once rooted, cuttings can be separated carefully and transplanted Root Cuttings • Using small pieces of roots to reproduce plants • should be three inches apart in rooting area Layering • Scarring a small area of stem to produce new plants – air layering – trench layering Trench Layering Division or Separation • Cutting or pulling apart plant structures for reproduction – bulbs – corms – rhizomes – tubers – runners – stolons – suckers Bulbs Grafting • Joining separate plant parts together so that they form a union and grow together to make one plant. Wedge Graft Approach Graft Grafting Terms • Scion-the piece of plant at the top of the graft • Rootstock-the piece of the plant at the root or bottom of the graft Methods of Grafting • If the scion and rootstock are the same size – wedge – splice – whip and tongue – approach Methods of Grafting • If the scion is smaller than the rootstock – cleft – side – notch – bark inlay Budding • A form of grafting when a bud is used – patch budding – T-budding – Chip Budding Chip Budding How to perform T-budding Step 2 Step 4 Step 1 Step 3 Tissue Culture • Using a small amount of plant tissue to grow in a sterile environment • The most plants in a short time • True to parent plant Advantages of Asexual Production • Plants mature in a shorter time • Budding is faster than grafting • In trench layering, a plant forms at each node on a covered stem • Some plants do not produce viable seed • New plants are the same as the parent plant Disadvantages of Asexual Reproduction • Some require special equipment and skills, such as grafting • Cuttings detach plant parts from water and nutrient source • Some plants are patented making propagation illegal The Uses of Biotechnology in Horticulture What is Biotechnology? • The use of cells or components (parts) of cells to produce products or processes Methods • Tissue culture or micropropagation • Cloning • Genetic Engineering Tissue Culture • Uses terminal shoots or leaf buds in a sterile or aseptic environment on agar gel or other nutrient-growing media to produce thousands of identical plants Cloning • Genetically generating offspring from non-sexual tissue Genetic Engineering • Movement of genetic information in the form of genes from one cell to another cell to modify or change the genetic make-up Benefits of Biotechnology • Produce many identical plants in a short time • Increase disease and insect resistance • Increase tolerance to heat and cold • Increase weed tolerance Benefits of Biotechnology • • • • Increase tolerance to drought Improve environment Increase production Other genetic changes