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Friday, January 3, 2014

Adaptability of plants: dandelion


Usually when researchers speaks about adaptive systems is intended of course, this apply in animal and artificial intelligence, since we can believe is needed a cognitive process, however, the plants have given us too much to learn in this area too.

In order to understand the process in other species more than animals, some plants have been object of study thanks to its ability to adapt to the environment and even annihilate other nearby plants, a plant in particular is peculiar due to its yellow flower and which is popularly known as dandelion but its scientific name is Taraxacum, which is posible to found  practically on all continents both in free areas in large cities, though they are native to Eurasia and America.

At least 3100 kind of taraxacums have been recognized of which only 500 are accepted species and varieties described as harmful plants for natural areas and gardens.

Its name comes from from French dent-de-lion, meaning lion's tooth. There are varieties of which reproduce sexually and others asexually, but it has been shown that those with more effective parthenogenesis are the asexual species, one of the most common explanations is that they have greater phenotypic plasticity due to the efficient selection of genotypes of general purpose.

However, some studies have showed that plants sexually reproduction have an advantage with respect to pests control and pathogens because sexual patterns produces genetically variables to allow  offspring  reduces the risk of infection.

The way in which some of these plants manage to cover extensive grounds is quiet simple and witty since its seeds float helped by the wind, wearing its form by way of parachute, so the strength of the wind can push them by wide sections.

In a study conducted by Honek, Martinkova and Saska (2005) it was found that seed dispersal takes place 10 days after flowering produced massively, however, only between 11 and 13% will land in the right place to grow a plant, since there are several predators around them, especially birds and beetles produce a need to develop a sustaintable way to survive.

Given the difficulty of plantation, a study conducted in 2000 found that the ability of this plant to populate large areas even with such low rate of sucessful plantation is because they have developed processes both cloning and recombination, which makes them a species capable of survive anywhere in the world.

It has been shown that dandelions and some other plants has two strategies of survival, which makes them peculiar to adaptive studies to such strategies called K & R that defines the ability of disturbance of the response of a population. Both terms are derived from the logistic growth equation, where K is equal to the environmental carrying capacity and R the intrinsic rate of population increase.

By what they called strategic play is characterized by the production of a large amount of seeds (or reproductive units) and high dispersion of the same, which potentiates the growth rate of a population given under environmental conditions that are capable of promoting growth, which makes them difficult to control plants.

The infestation level depends on the space the plant can occupy, in some places in the United States they can cover huge areas, while if chemical methods are applied consistently, they reproduce more controlled, but never disappear. 

In this context, I began to observe them in my own garden, where two different varieties can be found, one long and one short plant. 

In both cases they can be planted between the grass than on fertile land. Some ways to prevent them are chemical options, through liquids that affect only the roots, which is used by the city to eradicatethe amount of plants, or by mechanical methods which consists of boot plant from the root. However, this latter procedure is difficult because of the depth of the roots.

A third (not recommended) method, is pouring water boiling on the affected areas, but it should be taken into account that there is no selectivity in the process, whereupon all the roots are killed around, including grass.

The first year of observation implied recognition of the spaces that plants occupied and cleaning by mechanical methods. Something that catch my attention is the tendency to find them in the middle of the rose-bushes, which create an ideal space for its growth, however it doesn’t mean that the plant has the ability to choose the best place, but that I'm not so stupid to put my hands among the roses.
Its presence extends from the first weeks of spring, until the first weeks of autumn.  When temperature are  low, plants  disappear like the rest of perennials. 

During the summer, it is easy to see the flight of seeds, which are eaten by birds, beetles and some slugs around. The pace of  growing lowest between 75 and 85% in the third year of analysis but still be can’t be eradicated, since while there are plants in nearby areas and means of transportation, these will continue to grow.

I have seen other means of transportation as well as the air like the fur of pets, squirrels and other creatures or the feathers of birds. 

Surely, if you  has reached this article to the  end begins to ask your self: what is the relationship of the incredible ability of the dandelion to survive with learning?. Well, if you have not noticed it, because the species require biological and technological innovation to maintain its rate of growth and reproduction, as well as learning. The same answers cannot be used when the culture is not static.

In the next entry I will share a fascinating mathematical theory able to explain evolution.



References: 

Honek, A., Martinkova, Z., & Saska, P. ( 2005) Post-dispersal predation of Taraxacum officinale (dandelion) seeds. Journal of Ecology. 93 (2) 345-352.


Van Der Hulst, RGM., Mes, THM., Den Nijs, JCM., & Bachmann, K. (2000) Amplified fragment lenght polymorphism (AFLP) markers reveal that population structure of tripoid dandelions  (Taraxacum officinale) exhibits both clonality and recombination. Molecular Ecology. 9 (1) 1-8.


Verhoeven, KJF., and Biere, A. (2013) Geographic parthenogenesis and plant-enemy interactions in common dandelion. BMC Evolutionary Biology. doi:10.1186/1471-2148-13-23. Disponible en red: http://www.biomedcentral.com/1471-2148/13/23


Zimdahl, RL. (2007) Fundamental of Weed Science. Academic Press.  UK.

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