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 the oligosaccharides (dp: 3-9) - carbohydrates, Explain the Oligosa...

Explain the Oligosaccharides (DP: 3-9) - carbohydrates? Oligosaccharides consists of short chains of monosaccharide units joined by covalent bonds. The glycosidic bond may be α

Sexual reproduction, Normal 0 false false false EN-IN ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain early diastolic sound in diastolic, Explain Early Diastolic Sound i...

Explain Early Diastolic Sound in diastolic ? a) Opening snap (0s) of Rheumatic MS: High frequency sound. Generation of sound: Because of high LA pressure, the superior systolic

Polytene chromosomes, PO L YTEN E CHROMOSOMES First seen by Balb...

PO L YTEN E CHROMOSOMES First seen by Balbiani in salivary glands of larva of Chironomus insect (belongs to order Diptera). Later on such chromosomes observed in severa

Why is the development of bipedalism considered, Why is the development of ...

Why is the development of bipedalism considered to be a major advancement in human evolution?

Inter-relationships of classification, Inter-relationships of Classificatio...

Inter-relationships of Classification The aim of classification is to put together organisms on the basis of their similarities. But the question is what type of similarities?

What is the other name given to the sex chromosomes, Q What is the other na...

Q What is the other name given to the sex chromosomes? What is the function of the sex chromosomes? Sex chromosomes are also known as allosomes the other chromosomes that are n

Illustrate mitral valve orifice area, Q. Illustrate Mitral Valve Orifice Ar...

Q. Illustrate Mitral Valve Orifice Area? The normal mitral valve orifice in an adult is 4-5cm 2 when the valve is completely open in diastole. When the mitral valve orifice ar

Requirements and recommended dietary allowances (rda), Define Requirements ...

Define Requirements and Recommended Dietary Allowances (RDA)? What do we mean by requirements and RDA? The requirement level is the amount of nutrient needed to be absorbed to

Explain karyotype - animal taxonomy, Explain Karyotype - Animal Taxonomy? ...

Explain Karyotype - Animal Taxonomy? In animals systematic, it is the karyotype, that is the chromosome number and structure which are used quite extensively either separately

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