What is inbreeding depression in self pollinated crops?
Inbreeding depression is one of the leading factors preventing the evolution of self-fertilization in plants. In populations where self-fertilization evolves, theory suggests that natural selection against partially recessive deleterious alleles will reduce inbreeding depression.
Do self pollinated species show inbreeding depression?
No inbreeding depression
This phenomenon is mainly seen in the self- pollinated species as they do not show any inbreeding depression even though they do not show heterosis. It is because they reproduce both by self-pollination with developed homozygous balance and cross-pollination with heterozygous balance.
Why are self pollinating plants less susceptible to inbreeding depression?
Self-pollinating plants are naturally inbreeding and less susceptible to inbreeding depression due to the elimination of deleterious alleles by natural selection.
Why cross-pollinated species show more inbreeding depression than self pollinated species?
There is a positive-feedback between outcrossing and inbreeding depression. Because deleterious recessive alleles are constantly masked by outcrossing, these alleles persist. That in turn, favors a reproductive advantage and fitness for outcrossing over self-pollination.
What is the cause of inbreeding depression?
Conservation Genetics
Inbreeding depression occurs because species contain a load of rare harmful partially recessive alleles due to mutation-selection balance, and because some loci exhibit heterozygote advantage. Inbreeding increases homozygosity at these loci exposing harmful recessive alleles in homozygotes.
What is called inbreeding depression?
Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refers to an organism’s ability to survive and perpetuate its genetic material. Inbreeding depression is often the result of a population bottleneck.
Do self pollinating plants inbreed?
Selfing (self-pollination) is the ultimate form of inbreeding, or mating among close relatives. Selfing can create yield loss when inbreeding depression, defined as a lower survival and reproduction of inbred relative to outbred progeny, is present.
Why do self pollinated crops do not show ill effects of inbreeding depression Class 12?
Self-pollinated crop does not show the ill effects of inbreeding depression because the deleterious allele becomes homozygous and exhibits their lethal effect so it is eliminated by selection.
What are the main features of inbreeding depression?
Inbreeding depression occurs because species contain a load of rare harmful partially recessive alleles due to mutation-selection balance, and because some loci exhibit heterozygote advantage. Inbreeding increases homozygosity at these loci exposing harmful recessive alleles in homozygotes.
What are some examples of inbreeding depression?
This inbreeding may lower the population’s ability to survive and reproduce, a phenomenon called inbreeding depression. For example, a population of 40 adders (Vipera berus, shown at right) experienced inbreeding depression when farming activities in Sweden isolated them from other adder populations.
What are the causes of inbreeding depression?
Why does inbreeding depression occur?
Which plants do not show inbreeding depression?
》 Certain self-pollinated crops like rice, wheat, sorghum, ragi (finger millet), potato, tomato, groundnut, red gram, and chillies do not show inbreeding depression, may be due to their evolution.
What is inbreeding depression and its causes?
Inbreeding depression is the reduced survival and fertility of offspring of related individuals. Large effects are documented in wild animal and plant populations, as well as in humans. Intercrossing inbred strains improves yield (heterosis).
Which crop has highest inbreeding depression?
Based on degree of depression, the plant species can be grouped into 4 broad categories.
- High inbreeding depression: E.g. Lucerne, Carrot.
- Moderate inbreeding depression: E.g. Maize, Jowar, Bajra.
- Low inbreeding depression: E.g. Cucurbits, Sunflower.
What is the reason of inbreeding depression?