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

State about the blood ocular barriers of the eye, State about the blood ocu...

State about the blood ocular barriers of the eye? Blood Ocular Barrier: All vascular beds of the eye are highly permeable to lipoid soluble substances (oxygen, carbon dio

Define standardization - nutritional biochemistry, Define Standardization ...

Define Standardization - Nutritional  Biochemistry? One of the substances involved in a titration must be used as a standard for which the amount of substance present is accura

Biological sickness of soil, what is biological sickness of soil and its ma...

what is biological sickness of soil and its management

What is particularly of the mucous membranes, How would carbon monoxide poi...

How would carbon monoxide poisoning affect a person's coloring, particularly of the mucous membranes? How would it affect the hemoglobin concentration, hematocrit, and percent oxyh

Explain the hydration properties of proteins, Hydration Properties  Gen...

Hydration Properties  General conformation of individual proteins in solution is largely dependent on the interaction with water.  The progressive hydration of proteins startin

Nuclear type - endosperm, Nuclear Type - Endosperm The primary endosp...

Nuclear Type - Endosperm The primary endosperm nucleus divides. The cell wall is not laid. These nuclei and their division products form a large number of free nuclei. The fi

State the designations for horizons, State the Designations for Horizons  ...

State the Designations for Horizons  Of the several horizons, the master horizons are the results of the fundamental soil forming processes, viz. humification, eluviation  and

Morphological changes, Morphological changes Aquatic plants produce di...

Morphological changes Aquatic plants produce different kinds of leaves and produce aerenchyma (tissues with air gaps) where there be a need to do so. Also, a thick cuticle on

Visualize patient ductus arteriosus, Q. Visualize Patient Ductus Arteriosus...

Q. Visualize Patient Ductus Arteriosus? Best view to visualize a patient ductus arteriosus is high parasternal or ductal view. A patient ductus arteriosus in this view is see

Define mechanism for copper absorption, Define Mechanism for Copper Absorpt...

Define Mechanism for Copper Absorption? As in the case of other minerals, copper absorption appears to occur by two mechanisms: i) Saturable active mechanism, which operates

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