Pollination
Pollination is a process, in which pollen is transferred in the plant, i.e. from the male reproductive organ to the female reproductive of the plant. There are several different parts, which is essential in pollination. The pollen grain contains the male sex cell (gamete) to where the female gamete(s) is contained within the carpel. Pollination results in the production of genetically diverse offsprings. Pollination takes place in multiple ways, such as with the help of wind and animals. Plants, which are pollinated by animals, have a strong smell and brightly colored petals, whereas plants pollinated by winds are unscented and dull in color. It is essential in agriculture and horticulture. Pollination is of two types: abiotic and biotic pollination. Some flowers develop seeds because of self-pollination and cross-pollination.
History: Plants reproduce sexually was first demonstrated by a German botanist and physicist Rudolf Jakob Camerarius. Charles Darwin an eminent botanist, studied on seed dispersal and pollination and he labeled the co-evolution of plants and their pollinators as an "abominable secrecy".
Types of Pollination:
Abiotic pollination: The term abiotic pollination is used when pollination is mediated without the participation of other organisms. There are two primary abiotic vectors:
- Anemophily: This is a common form of abiotic pollination. Pollination is carried out with the help of wind and wind pollination is chancy. They are very common in grasses, most of the conifers and many deciduous trees. About 98% of pollination is carried out by wind.
- Hydrophily: Pollination is carried out by water, in the aquatic environments. Only 2% of pollination is carried out by sun and water.
Biotic pollination: The term biotic pollination is used when pollination is carried out with the help of organisms. They require pollinators, which can carry the pollen grains from the anther to the pistil or carpel. About 80% pollination is biotic. There are two basic biotic vectors:
- Entomophily: Insects are the most common type of animal pollinator. It occurs because the plants have brightly colored petals and have a strong smell to attract the insects. Bees, wasps, beetles, ants, flies, moths and butterflies are the insects, which carry out the biotic pollination.
- Zoophily: In this pollination is carried out by vertebrates like, bats and birds. Olfactory signals do not work for birds but they are known for their good vision. Birds like hummingbirds, spider hunters, sunbirds, and honeyeaters are the vertebrates, which carry out biotic pollination. Mechanics: Pollination can be accomplished by self-pollination and cross-pollination.
- Self-pollination: It occurs when pollen falls from the anther onto the stigma of the same flower, or to the another flower on the same individual plant. Plants generally needs to cross-pollinate, but some species of the plants have the ability to self-pollinate. It is also known as autogamy. Plants, which pollinate themselves and produce offsprings are called as self fertile. The self-pollinating plants include peanuts, strawberries and tomatoes.
- Cross-pollination: It occurs when the pollen travels from one flower to another flower of different flower. It is also known as syngamy. This type of pollination generates strong future generations with an increased genetic diversity. Plants, which cross-pollinate are said to be out crossing. It increases variation.
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