Pollination Basics-Part 1: Types of Pollination
Flower pollination is one of the crucial events in the life cycle of many flowering plants. When a
pollen grain moves from the anther (male part) of a flower to the stigma
(female part), pollination happens. This is the first step in a process that produces seeds, fruits,
and the next generation of plants.
Pollination Vocabulary
| Anther |
The part of the stamen where pollen is produced |
| Cross-pollination |
A type of pollination in which the pollen from the anther of a flower
is transferred to the stigma of a flower of another plant
|
| Filament |
The stalk that holds the anther and attaches it to the flower. |
| Nectary |
Nectaries are specialized nectar-producing structures of the flower |
| Ovary |
The enlarged basal portion of the pistil where ovules are produced. |
| Petal |
The parts of a flower that are often conspicuously colored |
| Pistil |
The ovule producing part of a flower. The ovary often supports
a long style, topped by a stigma. The mature ovary is a fruit, and
the mature ovule is a seed.
|
| Self-pollination |
A type of pollination in which the pollen from the anther of the
flower is transferred to the stigma of the same flower.
|
| Sepal |
The outer parts of the flower (often green and leaf-like) that enclose
a developing bud.
|
| Stamen |
The pollen producing part of a flower, usually with a slender filament
supporting the anther. |
| Stigma |
The part of the pistil where pollen germinates. |
| Style |
This is the name for the stalk of the pistil. When pollen reaches the
stigma, it begins to grow a tube through the style called a pollen tube,
which will eventually reach the ovary. The style therefore acts as a buffer
against pollen contamination, since only compatible pollen is able to
grow a pollen tube. |
Test your knowledge: Try the 'Identify the Parts of a Flower' quiz.
Although all flowering plants rely on pollination for reproduction, there is a variation in how plants pollinate.
There are two types of pollination: self-pollination and cross-pollination.
Self-pollination is the more basic type of pollination because it only involves one flower. This type of pollination
occurs when pollen grains from the anther fall directly onto the stigma of the same flower.
Although this type of
pollination is simple and quick, it does result in a reduction in genetic diversity because the sperm and egg cells
of the same flower share genetic information.
Cross-pollination is a more complex type of pollination that involves the transfer of pollen from the anther of one
flower to the stigma of a different flower.
This type of pollination results in an increase in genetic diversity because
the different flowers are sharing and mixing their genetic information to create unique offspring.
Cross-pollination is more complex than self-pollination because it requires the movement of pollen from one flower
to another flower.
There are several strategies that flowering plants utilize to move pollen from one flower to another
including: wind, water, and animal pollination.
Pollination can be observed first hand by watching the movements of animal pollinators. Animal pollinators are
organisms that travel from flower to flower and transfer pollen to each flower they visit.
This type of pollination is
very important because around 80% of all flowering plants and 75% of staple crop plants require animals to help
complete the pollination process. Some common animal pollinators that you may have seen flying from flower to
flower include bees, beetles, birds, flies, moths, bats, and butterflies.
Wind is commonly used to transport pollen long distances. Plants that use wind to transport pollen often have pollen
grains that are small, lightweight, and smooth. These plants are also often found in large populations because this
increases the chance of a pollen grain landing on a flower of the same species.
Although this strategy is not common, some plants rely on water to transport their pollen to other flowers. Water
transportation of pollen can involve rain water or waterways, such as streams.
Pollination — Part 2, Mechanisms of Pollination
The Benefits of Pollen
Host versus Nectar Plants: How It Works
Do Plants 'See'?
Do Plants 'Breathe'?