Xenogamy

Introduction

Xenogamy word refers to the transfer of pollen grains from the anther of one plant to the stigma of a different plant. This is one and the only type of cross-pollination that during pollination brings about genetically different types of pollen grains to the stigma. The term xenogamy (along with geitonogamy and autogamy) was first given by Kerner in the year 1876. Cross-pollination refers to the transfer of pollen grains from the flower of one plant to the stigma of the flower of another plant.

Xenogamy 

Xenogamy refers to the fertilization of a flower via the pollen grains of a genetically different flower belonging to the same species. It is the typical form of cross-pollination method in which genetically modified offspring are formed. Xenogamy can also occur via external pollinating agents. Flowers that use hydrophily possess a long stigma along with unwettable floral parts. Concerning, flowers that use anemophily are generally smaller in size and involve exerted stigma and anthers. Flowers that are pollinated mainly by zoophily exhibit many different characteristics like those of brightly coloured petals, nectar, and scents. Entomophily, omithophily and malacophilous are some of the forms of zoophily.

Difference Between Xenogamy and Geitonogamy 

Xenogamy: refers to the fertilization of a flower via the pollen of a flower from a genetically different plant.

Geitonogamy: is the fertilization of a flower via pollen from another flower of the same plant.

Type of Pollination

Xenogamy: it is a method of self-pollination.

Geitonogamy: it is only functionally a cross-pollination method while genetically it is a self-pollination method.

Contribution to Evolution

Xenogamy: this type of pollination produces offspring having genetic variations as compared to the parents. Thus, it has contributed to its evolution.

Geitonogamy: this results in genetically identical offspring. Thus, it has no contribution to evolution.

The Adaptations in Flowers

 Xenogamy: Herkogamy, dichogamy, self-incompatibility, male sterility, and heterostyly are some of the common adaptations in xenogamy flowers.

Geitonogamy: various forms of geitonogamy flowers are usually situated on the same stem.

Advantages

 Xenogamy: it produces genetically modified offspring that possess different characteristics from the offspring.

Geitonogamy: this can maintain the parental characters of the race indefinitely.

Disadvantages

Xenogamy: The efficiency of seed production is based on the external pollinating agents.

Geitonogamy: excess amounts of force must be generated to be pollinated by external pollinating agents.

Examples

Xenogamy: Squash, onions, broccoli, spinach, willows, grasses and olive trees are some of the common examples of xenogamy.

Geitonogamy: Corn is one of the most common examples of geitonogamy.

Conclusion

Xenogamy is mainly the deposition of pollen grains of one flower onto the second flower in a different plant belonging to the same species. Here, generally, two plants are genetically different though they belong to the same species. Hence, genetically modified offspring are produced by xenogamy. Hence, xenogamy can be considered more beneficial than self-pollination. The majority of flowers bear adaptations to promote cross-pollination. The main difference between allogamy and xenogamy is in the pollinating processes. Here we come to an end of this topic, we hope that you were able to grasp a clear concept of the topic. We suggest you grasp the concepts rather than just mugging them up.