Plant cloning

Natural cloning

• propagated rom the stem, leaf, bud or root

• Eventually becomes independent from the parent plant

• New plants are genetically identical to the parent plant

• Bulbs

  • Fleshy layers that store nutrients

• Runners

  • Horizontal growing stems above ground

  • Also called stolons

• Stem tubers

  • Thickened stems acting at storage organs with buds that can grow into new plants

  • Tubers can be dug up and grown into new plants eg potatoes

• Rhizomes

  • Horizontal growing stems below ground

  • Can be cut into shorter sections and grown to create new plants eg ginger

• Cuttings

  • Natural cloning in horticulture

  • Advantages

    • Faster production of new plants

    • Multiple new plants can be made from one parent plant

    • Guarantees the quality of the plant as it is a clone

  • Disadvantages

    • Lack of genetic variation so cloned plants may be susceptible to new pests or diseases

Artificial cloning

• Explant collection

  • Small tissue samples are taken from a parent plant to start the micropropagation process

  • Explants are typically taken from the stem and root tips as they have meristem cells

  • Meristem cells are totipotent so can differentiate into any type of plant cell

• Sterilisation

  • Cells sterilised to remove and inhibit contaminant growth

• Culture

  • Cells in each explant divide to form an undifferentiated mass of cells called a callus

  • Callus cells transferred to a new medium with specific conditions to promote root and shoot formation

  • Allows callus cells to differentiate and develop into plantlets

• Transfer

  • Fully formed plantlets complete with shoots and roots are moved to a growth medium like soil

  • Can then develop