Gametophytic incompatibility, Biology

Assignment Help:

Gametophytic Incompatibility

In GSI systems callose deposition is not evident on the stigma but is very conspicuous in the pollen tube. Sometimes the callose deposition occurs even in the germpore, inhibiting pollen germination. In the Poaceae, the rejection reaction is completed within a few minutes after pollination and subsequent rejection or acceptance takes 10 minutes with the exception of Poaceae and Oenothera, the recognition/rejection reaction in GSI system occurs after the pollen tube has grown about two third the length of the style.

Genetically the recognition factor on the male side has been attributed to the male gametophyte; the proteins incorporated during pollen wall development in the intine are involved. Since in GSI systems the rejection reaction is comparatively delayed, is also possible that the synthesis or activation, and release of the recognition substances are also delayed and they occur in the pollen tube. In some species the tubes show reduced level of carbohydrates and starch.


Related Discussions:- Gametophytic incompatibility

Explain subphylum vertebrata, Subphylum  Vertebrata : (41,700 species, th...

Subphylum  Vertebrata : (41,700 species, the vertebrates) Vertebral column of bone or cartilage, head is well developed, heart is ventrally situated dorsal aorta, two pairs of

Explain tropical rain forests in biomes, Explain Tropical Rain Forests in b...

Explain Tropical Rain Forests in biomes? You probably are well aware of the danger that the world's rain forests are facing in terms of extinction! There are huge numbers of sp

Kin and group selection, Before we proceed to discuss kin selection we shou...

Before we proceed to discuss kin selection we should define the term altruism. It refers to the behaviour pattern of an individual in the population for the benefit of other member

How did the industrial revolution in england, How did the industrial revolu...

How did the industrial revolution in England offer an example of natural selection? One of the classic instances of natural selection is regarding the moths of industrial zones

Which disease is associated with rapid dehydration, Which disease is associ...

Which disease is associated with the following symptoms? Sudden onset of profuse watery stool followed by vomiting, rapid dehydration and muscular cramps?

Tuberculosis, T ub e rc u l o si s Tuberculosis in animal is ca...

T ub e rc u l o si s Tuberculosis in animal is caused by Mycobacterium bovis , M. tuberculosis and M. avium and among these the most important causal agent is M.

Criteria for identifying biodiversity hot spots, A simple method used to id...

A simple method used to identify areas of high conservation priority is the selection of countries according to highest species richness. Among the top 12 countries identified this

Protozoa, what are disadvantage of protozoa

what are disadvantage of protozoa

Digestion of food materials, DIGESTION OF FOOD MATERIALS Digestion, you...

DIGESTION OF FOOD MATERIALS Digestion, you know, involves  the mixing of  food, its movement through the digestive tract and chemical breakdown of the large ntolecules of  food

Define unsafe water and sanitation - public nutrition, Define Unsafe Water ...

Define Unsafe Water and sanitation - public nutrition? Safe water and sanitation may seem tenuous in their link to food security but their impact is unquestionable. With 19% US

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd