Plant Cloning: Micropropagation

What is micropropagation?

Producing many genetically identical plant clones from one parent using tissue culture

What is a tissue culture?

Plant tissue grown in a sterile nutrient medium containing growth hormones

Which hormones are used in plant tissue culture?

Auxins and cytokinins

What is an explant?

A small tissue sample taken from a parent plant for tissue culture

Where are explants usually taken from?

Stem tips and root tips

Why are explants taken from stem tips and root tips?

They contain meristem cells

What are meristem cells?

Undifferentiated cells that can divide and differentiate

What does totipotent mean?

Able to differentiate into any type of plant cell

What is the first step of micropropagation?

Collect small tissue samples called explants

Why are explants sterilised?

To remove and prevent growth of bacterial and fungal contaminants

Why is sterilisation important in micropropagation?

It reduces infection and helps produce healthy crops

What happens during the culture stage of micropropagation?

Sterilised explants are placed on a nutrient rich medium

What does the culture medium provide?

Minerals sugars vitamins and growth hormones

What is the function of auxins in tissue culture?

They stimulate cell division and growth

What is a callus?

An undifferentiated mass of cells formed by cell division

How is a callus formed?

Cells in the explant divide by mitosis

How are plantlets produced from a callus?

The callus is transferred to a new medium that encourages shoot and root formation

What happens when callus cells develop into plantlets?

They differentiate into specialised plant tissues

What is a plantlet?

A young plant with shoots and roots

What happens to plantlets after they develop?

They are transferred to a growth medium such as soil

What do plantlets develop into?

Mature plants genetically identical to the parent

What is the first stage of micropropagation?

Explant collection

What are the five main stages of micropropagation?

Explant collection

sterilisation

culture

development

transfer

How is micropropagation used for rare plants?

It rapidly produces large numbers of plants from rare or endangered species

How is micropropagation used in agriculture?

It produces large numbers of uniform crop plants

How can micropropagation help prevent crop disease?

It can produce disease free clones

How can micropropagation support conservation?

It helps preserve valuable genetic resources

How can micropropagation produce genetically modified plants?

It allows mass production of plants engineered with desired traits

How can micropropagation help produce seedless plants?

It can clone seedless plants without relying on seed production

Why is micropropagation useful for plants difficult to grow from seeds?

It produces new plants directly from tissue

What is an advantage of micropropagation for desirable traits?

It produces genetically identical plants that reliably inherit desirable traits

Why can micropropagation be carried out all year?

It takes place under controlled conditions

Why is micropropagation space efficient?

Many plants can be grown in a small area

How quickly can micropropagation produce plants?

It can rapidly produce large numbers of mature plants

What is a major genetic disadvantage of micropropagation?

Genetically identical plants have little genetic variation

Why are micropropagated crops vulnerable to disease?

A disease may affect all genetically similar plants

Why are micropropagated crops vulnerable to environmental changes?

Low genetic variation reduces the chance of resistance to changing conditions

How can micropropagation spread undesirable traits?

Undesirable traits in the parent may be copied into every clone

Why is micropropagation expensive?

It requires specialised equipment sterile conditions and skilled technicians

Why can infection cause major losses in micropropagation?

Explants and plantlets are vulnerable to contamination