Ecades and ecotype

Ecades and ecotype - Ecades��•introduction �•Definition�•Explanation�•types of ecades , Ecotype, • introduction, •Definition ,•Ecotype VS. species ,•How did ecotype appear ,•From ecotype to species, •Example

1. Ecades and ecotype By- Sneha sahu M.Sc. 3 rd semester in botany

2. Ecades • introduction •Definition •Explanation •types of ecades Ecotype • introduction •Definition •Ecotype VS. species •How did ecotype appear •From ecotype to species •Example Content

3. Ecades

4. Introduction The ecads otherwise known as ecophenes are genetically similar but morphologically distinct in response to different environmental conditions. Gote Turesson (1922), a Swedish worker conducted a series of experiments on variations within a Swedish plant species Plantago maritina. H e first gave the term "Ecads" or "Ecophenes". Definition 1.an organism or kind of organism (such as a species)  modified by environment 2 . a nonheritable somatic modification induced by environment : an acquired character.

5. Explanation He collected a group of 20 or more individuals of the same species from different areas and planted them under identical environmental conditions in his experimental garden at Akark. He noted that. Several intergrading forms existed within the species which differed from one another in morphological or physiological features and Some of differences might be unstable and induced only by the environmental factors while some others might be permanent (i.e., genetically fixed).

6. Conti… The population sampling and subsequent procedures that Turesson followed led him to conclude that species differ from one another morphologically, physiologically and in habitat requirements and on the basis of such studies he proposed the following classes of morphological forms within a species. 1. Ecads or Ecophenes or Habitat forms, 2. Ecotypes. 3. Ecoclines, 4. Ecospecies and 5. Coenospecies.

7. Conti Ecads are also called epharmones or habitat forms which are environmentally induced variations. They belong to the same genetic stock or species and the variations in their morphology (in shape, size, number and reproductive capacity) are induced by the environmental influences. The variations are not fixed batk are temporary, somatic and reversible. If one type of ecad is transplanted into environment of another type of ecad, the differences would disappear. These morphological variations are not permanent because the genetic composition of ecads is not affected and so they are identical in their genetic behaviour and inter-fertile. The variants or ecophenes may differ to such an extent that they can be treated as separate species. Euphorbia plants growing in the grassland are prostrate and profusely branched while he plants of the same species growing on the footpaths are compact small leaves and cushioned.

8. Conti. When these forms are grown under identical habitat conditions their differences disappear. In Bothriochloa pertusa and Dichanthium caricosum several distinct morphlogical forms of ecads have been noted under different habitats by Pandeya (1962). Types of ecades In both the species there are two types of ecads: (i) Basket form habit shown by the plants growing in protected areas, and (ii) Saucer-shaped habit of the plants growing in over-grazed areas. Grazing causes reduction in the size of erect stem, number of spikes per raceme, number of spikelets per spike and in length and breadth of lower glumes of spikelets. In addition to these morphological variations, some physiological variations are also noticed, as for example development of anthocyanine in the leaves and early initiation of flowers.

9. Ecotype

10. Introduction genetically race within a species, which isk It describes distinct geograplue a variety. population or genotypically adapted to specific environmental conditions. Typically, though ecotypes exhibit phenotypic differences (such as in morphology or physiology) stemming from environmental heterogeneity, they are capable of interbreeding with other geographically adjacent ecotypes without loss of fertility or vigor.

11. Definition An Ecotype is a population of species that differs genetically from other populations of the same species because local conditions have selected for certain unique physiological or morphological characteristics. Broader than a biotype and narrower than species. Ecotype •While species are a more broad category, ecotypes are narrowed down more specifically. •These specifics can involve area of growth, a particular photo period, structure, etc. (Source: Life: The Science of Biology)

12. How did ecotype appears Ecotypes appeared in response to a process of natural selection within species. • In order to more effectively survive within a specific climate, region, etc; ecotypes developed. From ecotype to Specie’s An ecotype may become a species if natural selection leads to further variations within itself In this case, the ecotype would take the form of a new species and its variations would be new ecotypes

13. Example