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

Autoradiography, Autoradiography is the process to detect radioactively la...

Autoradiography is the process to detect radioactively labeled molecules (which commonly have been separated in an SDS-PAGE or agarose gel) based on their ability to develop an im

Basic morphological features of echinoderms, Q. What are the basic morpholo...

Q. What are the basic morphological features of echinoderms? Echinoderms, as the name indicates (derma = skin, echino = spiny), are creatures with spines originated from an end

Morphological and anatomical evidences of evolution, MORPHOLOGICAL AND ANAT...

MORPHOLOGICAL AND ANATOMICAL EVIDENCES - (i ) HOMOLOGOUS ORGANS - The organs apparently similar or dissimilar in structure and function, but of similar embryonic origi

Of which substance are microtubules made, Of which substance are microtubul...

Of which substance are microtubules made? In which structures and cellular processes do microtubules participate? Microtubules are made of consecutive dimers of the protein tub

Presence and constancy - synthetic characters, Presence and Constancy - Syn...

Presence and Constancy - Synthetic Characters Presence and constancy refer to how uniformly a species occurs in different stands in a community. For example, when a species is

Functions of stomata, Functions of Stomata The cuticle forms outermost...

Functions of Stomata The cuticle forms outermost surface of the leaf and offers resistance to the evaporation of water vapour and entry of carbon dioxide necessary for photosy

What is the result of post myocardial infarction ventricular, What is the r...

What is the result of Post Myocardial Infarction Ventricular ? Results: Hospital mortality may be as high as 30 per cent. This depends on the extent of infarction and- pre-op

Discuss briefly the color reactions of proteins, Question 1 List variou...

Question 1 List various methods used for determination of blood glucose. Explain the principle of each test. Add a note on advantages and disadvantages of each method Qu

Why does dna twist, Why does DNA twist? If it did not twist, would you...

Why does DNA twist? If it did not twist, would you expect it to fit into the miniscule cell? As we all know, if we join all of the DNA molecules from a person's body end to en

Write the definition of counselling, Q. Write the definition of counselling...

Q. Write the definition of counselling? The counselling process, involves various steps in a sequence as given below: 1. Rapport-Building 2. Locating the Problem 4. Pl

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