Plant Reproduction: Sexual, Asexual, and Propagation Methods

What is sexual reproduction in plants?

Fusion of two gametes

What are the advantages of sexual reproduction?

Increases genetic diversity, creates a seed bank, and allows larger dispersal area

What are the disadvantages of sexual reproduction?

Energy intensive and requires finding a mate

What is asexual reproduction in plants?

Reproduction without seeds

What are the advantages of asexual reproduction?

Quick, requires less energy, no need for pollination or dispersal, maintains parent genetics, no seed germination required, and is economically efficient

What are the disadvantages of asexual reproduction?

Decreased genetic diversity, no seed bank, and limited dispersal

What are the 6 examples of vegetative reproduction methods?

Rhizome, tuber, corm, bulb, stolon, and plantlets

What are artificial methods of vegetative propagation?

Cuttings (leaf, stem, root), layering, division, and grafting

What are the 2 main types of sexual reproduction in plants?

self-pollination, and cross-pollination

What is self-pollination (selfing)?

Pollen fertilizes the same plant

What is cross-pollination (outcrossing)?

Pollen from one plant fertilizes another plant

What is tissue culture (micropropagation)?

Growing plant cells in a sterile medium to produce new plants

What is a callus?

A mass of undifferentiated plant cells formed during tissue culture

How does tissue culture begin?

A small piece of plant tissue is cut and placed in agar medium

What happens when hormones are added to the medium in tissue culture?

A callus forms and cells begin to differentiate

How do you induce root formation in tissue culture?

By adding auxin

How do you induce shoot formation in tissue culture?

By adding cytokinin

What are the steps of micropropagation?

Cut tissue, incubate in agar, add hormones, form callus, differentiate roots and shoots, transplant to soil

What are the advantages of tissue culture?

Consistent genetics, rapid production, small starting material needed, season independent, useful for difficult species

What are the disadvantages of tissue culture?

High cost, requires expertise, risk of contamination, high failure rate, requires disease screening

What are the advantages of self-pollination?

No need for a mate, useful in scattered populations, allows colonization, saves pollen, increases fertilization success

Why does self-pollination increase fertilization success?

Shorter distance for pollen transfer and reduced exposure to drying and UV

What are the disadvantages of self-pollination?

Reduced genetic diversity and risk of inbreeding depression

What is inbreeding depression?

Reduced survivability and fertility of offspring from closely related individuals

What is outcrossing?

Pollination between different plants

What is facultative outcrossing?

Plants can self-pollinate or cross-pollinate

What is obligate outcrossing?

Plants can only cross-pollinate

What are the three mechanisms that prevent self-pollination?

Genetic, temporal, and structural

How does genetic self-incompatibility prevent self-pollination?

The S-locus recognizes and rejects pollen from the same plant

What is the S-locus?

A genetic system with multiple alleles that controls self-recognition in pollen

How does temporal separation prevent self-pollination?

Pollen and stigma mature at different times

How does structural separation prevent self-pollination?

Stigma and anthers are positioned to reduce contact