Saturday, September 18, 2010

Pollination Process

By definition as I learn in university we can say that Pollination is the process by which pollen is transferred in plants and thereby enabling fertilization and sexual reproduction. For many thousand years the plants went through the pollination process naturally before modified by humans for improvement in certain crops. The writers about to share the knowledge about pollination process in agriculture technology based on my reading and own experience during the tenure in agriculture sector for more than 25 years especially in agriculture extension program.

The pollination process occurred when the pollen grains in which contain the male gametes (also known as sperm) to where the female gamete(s) are contained within the carpel in gymnosperms the pollen is directly applied to the ovule itself. The receptive part of the carpel is called a stigma in the flowers of angiosperms. The receptive part of the gymnosperm ovule is called the micropyle. Pollination is a necessary step in the reproduction of flowering plants, resulting in the production of offspring that are genetically diverse. The flower has male components and female components.

The study of pollination process we has to brings together many disciplines, such as botany, horticulture, entomology, and ecology. The pollination process as an interaction between flower and vector. Flower may appear in many attractive different colors, produce aromatic aroma, sweet taste or nectar, various size and light to attract their pollinators, The pollinators came to the flowers to collect their food (either nectar, pollen, flesh others) from one flower to other huge numbers of similar or different flower and the pollination process continued.

Pollination process is an important part in horticulture and agriculture because it determines fruiting activity to produce crop yield. Most crop harvest depends on fertilization success rate and known as the result of pollination. The plant breeder work hard to do research in new crop with meet the farmers need such as high yielding varieties, resistance to most diseases, resistance to pests attack, shorter growing period, able to adapt the bad weather and other special character. The research uses pollination process as a method to do their research base and conducted in laboratory or in farm.

Pollination process may occurred by Abiotic pollination or Mechanical pollination. For Abiotic pollination it will refers to situations where pollination is mediated without the involvement of other organisms or in other words the pollinators. From so many plants found in the world the study shown that only 10% of flowering plants are pollinated without animal assistance. The most common form of abiotic pollination is anemophily which was pollinated by wind. This flower normally is very light and able to float to a such distance by wind. This form of pollination is predominant in grasses most conifers and many deciduous trees. The easiest plant is Lalang (Imperica cylindrica) which produce white light flower and able to float on air during maturity period to travel for new places.

Second abiotic pollination process is called Hydrophily is pollination by water and occurs in aquatic plants which release their pollen directly into the surrounding water. Of the 20% of abiotically pollinated species, 98% is by wind and 2% by water. This plants normally grow on wet area and the pollination occurred with the water existence. Plants in this world mostly fall under biotic pollination process about 80% from the total.

Biotic pollination the process of pollination requires pollinators or organisms that carry or move the pollen grains from the anther to the receptive part of the carpel or pistil. This is biotic pollination. The various flower traits (and combinations thereof) that differentially attract one type of pollinator or another are known as pollination syndromes. The many characteristic of plants varieties and species produces different traits for the plant breeders to use pollination process as a base of their research and produce new plants varieties. The controlled pollination process and laboratory treatment to the male and female parts combined for new crop generation.

From the biodiversity system it was found that there are roughly 200,000 varieties of animal pollinators in the wild. According to scientific study most of which are insects. Insect lives within the plants to get their foods from the flowers and other components. Entomophily is a pollination by insects which often occurs on plants that have developed colored petals and a strong scent to attract insects such as, bees, wasps and occasionally ants (Hymenoptera), beetles (Coleoptera), moths and butterflies (Lepidoptera), and flies (Diptera). In zoophily the pollination is performed by vertebrates such as birds and bats. But particularly in hummingbirds, sunbirds, spiderhunters, honeyeaters, and fruit bats. Plants adapted to using bats or moths as pollinators typically have white petals and a strong scent, while plants that use birds as pollinators tend to develop red petals and rarely develop a scent (few birds have a sense of smell).

For Mechanical Pollination it was a Pollination can be accomplished by cross-pollination or by self-pollination which is defined as follows. Cross-pollination or also called allogamy occurs when pollen is delivered to a flower from a different plant. Plants adapted to outcross or cross-pollinate often have taller stamens than carpels or use other mechanisms to better ensure the spread of pollen to other plants' flowers. Cross pollination may result a change in the next seeds and plants characteristic when it received different traits or pollen from other suitable plants. This will produce new crop varieties in plant breeding technology.

Self-pollination occurs when pollen from one flower pollinates the same flower or other flowers of the same individual. It is thought to have evolved under conditions when pollinators were not reliable vectors for pollen transport, and is most often seen in short-lived annual species and plants that colonize new locations.Self pollination may include autogamy, where pollen moves to the female part of the same flower; or geitonogamy, when pollen is transferred to another flower on the same plant. Plants adapted to self-fertilize often have similar stamen and carpel lengths. Plants that can pollinate themselves and produce viable offspring are called self-fertile. Plants that can not fertilize themselves are called self-sterile, a condition which mandates cross pollination for the production of offspring.

Terminology for Cleistogamy is defined as self-pollination that occurs before the flower opens. The pollen is released from the anther within the flower or the pollen on the anther grows a tube down the style to the ovules. It is a type of sexual breeding, in contrast to asexual systems such as apomixis. Some cleistogamous flowers never open, in contrast to chasmogamous flowers that open and are then pollinated. Cleistogamous flowers by necessity are self-compatible or self-fertile plants. Many plants are self-incompatible, and these two conditions are end points on a continuum.

Pollination also requires consideration of pollenizers. The terms "pollinator" and "pollenizer" are often confused: a pollinator is the agent that moves the pollen, whether it be bees, flies, bats, moths, or birds; a pollenizer is the plant that serves as the pollen source for other plants. Some plants are self-fertile or self-compatible and can pollinate themselves (e.g., they act as their own pollenizer). Other plants have chemical or physical barriers to self-pollination.

In agriculture and horticulture pollination management, a good pollenizer is a plant that provides compatible, viable and plentiful pollen and blooms at the same time as the plant that is to be pollinated or has pollen that can be stored and used when needed to pollinate the desired flowers. Hybridization is effective pollination between flowers of different species, or between different breeding lines or populations. Pollination is very important process to ensure plant survival from many decades.


M Anem

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