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 following terms in detail - homology, Explain the following ter...

Explain the following terms in detail - Homology, Homologous ? Structures that have a similar evolutionary origin however different functions. The wing of a bat and a whale's fl

Define immediate preoperative period during surgery, Define Immediate Preop...

Define Immediate Preoperative Period during Surgery? Nothing should be given by mouth for at least 8 hours before a general surgery so that the stomach has no leftover food at

Tropical deciduous forests, Rainfall is high, sometimes higher than tropica...

Rainfall is high, sometimes higher than tropical rain forests but seasonal. There are pronounced wet and dry periods, and so are winter and summer seasons. The soils are brown in c

Mold, Does mold have roots? When mold is inside on wood - are there roots t...

Does mold have roots? When mold is inside on wood - are there roots that go into substrate? I am trying to find this out today if possible to evaluate a remediator''s plan. I am wo

Explain differential staining technique, Explain Differential Staining Tech...

Explain Differential Staining Technique? It divides bacteria into separate groups based on staining properties, like Gram's stain, Acid-fast stain etc. Here 2 or more contrasti

Define titrimetric estimation of carbohydrates, Define Titrimetric Estimati...

Define Titrimetric Estimation of Carbohydrates? The Fehling's Soxhlet method is the commonly used method for titrimetric estimation of carbohydrates. In the following section y

Endocrine glands - gastro-intestinal mucosa, GASTRO-INTESTINA L MUCOSA - ...

GASTRO-INTESTINA L MUCOSA - It develops from the endoderm of the embryo. Inner most layer of the wall of the alimentary canal is called mucosa. Certain cells of the mucosa

Are mollusc metameric beings, Are mollusc metameric beings? Exclusively ana...

Are mollusc metameric beings? Exclusively analyzing this feature could it be said that molluscs are evolutionarily proximal to nematodes or to annelids? In molluscs there is no

Enumerate in detail about the cytoskeleton, Enumerate in detail about the C...

Enumerate in detail about the Cytoskeleton All eukaryotic cells have distinct shapes, and are also capable of assuming different shapes. 'The internal organelles of a cell are

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