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 non-starch polysaccharides, NON-STARCH POLYSACCHARIDES A polysa...

NON-STARCH POLYSACCHARIDES A polysaccharide often termed as complex carbohydrate. Besides starch, a mixture of substances called non starch polysaccharide (NSP), also constitut

Disorders of liver, DISORDERS OF LIVER: In the foregoing  sections and...

DISORDERS OF LIVER: In the foregoing  sections and sub-sections we have discussed about the common disorders of upper and lower gastrointestinal  tract. Now we shall discuss

Define about the iodine toxicity, Define about the Iodine Toxicity? A w...

Define about the Iodine Toxicity? A wide range of iodine intakes is tolerated by most individuals, owing to the ability of the thyroid to regulate total body iodine. This toler

Functions of the vascular system, Functions of the Vascular System The...

Functions of the Vascular System The major function of the circulatory system is to provide a transport mechanism for the blood flow to and from the heart. The vascular syste

The human abo blood type codominant alleles a and b, The human abo blood ty...

The human abo blood type codominant alleles a and b are dominant to O. A man with blood type B and women with blood type A could potentially have children with which of the followi

Typological species concept, The typological species concept was suggested ...

The typological species concept was suggested by Plato more than 2000 years ago. According to this concept, the immense variety in nature can be reduced to a few "types". Individua

What is the capillarity, What is the capillarity? How this phenomenon chemi...

What is the capillarity? How this phenomenon chemically explained? What is relevance of the capillarity for water transport in plants? The Capillarity is the phenomenon through

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