(3.7) Asexual reproduction

What are methods of natural asexual reproduction in plants?

Runners

Tuber

Bulbs

Describe: how do runners work?

some plants grow horizontal side stems with plantlets at their ends

on touching soil, the plantlets grow roots, grow and become independent

growing into a genetically identical plant

Describe: how do bulbs work?

Underground food storage organs which act as food storage organs

• layers of embryonic leaves

• or short stems

shoots appear when the bulb leaves its dormant phase

Describe: how do tubers work?

tubers are short, thick stem with ‘eyes’ that can grow to new plants

What are the methods of artificially cloning plants?

Cuttings

Artificial propagation

Grafting

Describe: how do cuttings work?

a cutting is taken from good parent plants

dipped in rooting powder (containing rooting hormones)

placed in water until roots grow/placed in soil

planted and grow into identical adult plants

Describe: how does grafting work?

healthy stem is sliced + a compatible cutting is attached

stem + cutting bind and grow together

Describe: how does artificial propagation work?

Tissue samples form parent plant

placed in agar growth medium with nutrients

samples → plantlets

plantlets planted to grow into clones of parent

What are the advantages of asexual reproduction?

Helpful for industry

• efficient, cheap process

• can ensure desirable characteristics

What are the cons of asexual reproduction?

lack of genetic variation → risk of disease