The types and methods of pollination in the plants
Reproduction in plants
The plant reproduction is the process by which plants generate new individuals , there are two kinds of reproduction in the plants which are the sexual reproduction & the asexual reproduction , The flowers are classified according to the sex into three types which are the male flower , the female flower and the bisexual ( hermaphrodite ) flowers .
The male flowers contain only male reproductive organs ( the androecium ) and they are unisexual such as the palms , the maize & the pumpkins , The female flowers contain only female reproductive organs ( the gynoecium ) and they are unisexual such as the palms , the maize and the pumpkins , The bisexual ( hermaphrodite ) flowers contain both the male & female reproductive organs such as the tulip , the petunia and the wallflower .
Sexual reproduction in plants happens via the flowers , it takes place in two successive processes which are the pollination and the fertilization , it is the formation of offspring by the fusion of gametes while asexual reproduction is the formation of offspring without the fusion of gametes .
The pollination is the process of transfer of pollen grains from the flower anthers to the stigmas , the pollen grains are small cells that formed in the anther inside the pollen chamber , When those grains become mature , the anther splits longitudinally and the pollen grains spread in the air like the dust .
Types of pollination
There are two types of pollination which are self ( auto ) pollination and mixed ( cross ) pollination , Self ( auto ) pollination is the transfer of pollen grains from the anthers of a flower to the stigmas of the same flower or to another flower in the same plant , Mixed ( cross ) pollination is the transfer of pollen grains from the anthers of a flower to the stigmas of another flower in other plant of the same kind .
If the flowers are on two different individual plants , the flowers have been cross pollinated , and if the flowers are on the same individual or if the anther and the stigma are in the same flower , the flowers have been self pollinated .
The flowers that are self pollinated and they can produce the viable seeds are self compatible , and the flowers which are self pollinated but the pollen grains does not function properly on the carpels of the same plant are termed self incompatible .
Methods of mixed ( cross ) pollination
The pollen grains are transferred from one flower to another by different ways which are the pollination by wind , the pollination by insects and the artificial pollination .
Pollination by air
The flowers which are pollinated by the air are characterized by : their anthers are hanged to be easily opened by the air , and their stigmas are feathery like and sticky to catch the pollen grains from the air .
The flowers produce huge numbers of pollen grains to compensate what are lost in the air , and their pollen grains are light in weight and dry to be easily carried by the air .
Pollination by insects
The flowers pollinated by the insects are characterized by : their petals are colored and scented to attract the insects to feed on its nectar , and their pollen grains are sticky or having coarse surfaces to stick on the insect body .
The artificial pollination is carried out by man , man has to pollinate the palm trees to ensure the pollination process as the pollination is difficult to occur by the air or by insects , where the gardener spread the palm tree’s pollen grains over their female flowers .