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

What are seed gums, What are seed gums? What are its characteristic propert...

What are seed gums? What are its characteristic properties? Seed gums are a group of polysaccharides with the following properties: light to dark cream colored amorphou

Explain culture characteristics of molds, Q. Explain Culture Characteristic...

Q. Explain Culture Characteristics of Molds? The gross appearance of a mold growing on a food often is sufficient to indicate its class or order. Some molds are loose and fluff

Bacteria, explain anatomy of bacteria

explain anatomy of bacteria

What is the typical localization of the tropical forests, What is the typic...

What is the typical localization of the tropical forests regarding latitude? The Tropical rain forests, like the Congo forest and the Amazon forest, are typically located in lo

Define functions of selenium in humans, Define Functions of selenium in hum...

Define Functions of selenium in humans? Until recently, the only known metabolic role of selenium in humans was as a component of glutathione peroxidase which along with vitami

Ciliated protozoan, Ciliated Protozoan Ciliates form the largest and t...

Ciliated Protozoan Ciliates form the largest and the most homogenous group of protozoans. They are placed under one phylum Ciliophora and evidence indicates that its members s

Explain about the thiamin - vitamin b or aneurin, Explain about the Thiamin...

Explain about the Thiamin - Vitamin B or aneurin? Thiamin is one of the earliest recognized vitamins. The chemical structure of thiamine was established by Williams in 1936. Th

Reproduction., in oogenesis only on functional egg cell is normally formed ...

in oogenesis only on functional egg cell is normally formed from primary oocyte. Briefly explain

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