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

Differentiate between glycogenesis and glycogenolysis, Differentiate betwee...

Differentiate between glycogenesis and glycogenolysis. The synthesis  of glycogen in liver and muscle  is  called glycogenesis.  The breakdown of glycogen in the liver (glycoge

Heparinisation, Heparinisation Blood when allowed to flow out from ...

Heparinisation Blood when allowed to flow out from body to the circuit tubings can get clotted. To prevent this, heparinisation is done. Patient is administered 3 mg

Give examples of both aerobic and anaerobic exercises, Give examples of bot...

Give examples of both aerobic and anaerobic exercises Games like foot ball and basket ball, involve  both aerobic and anaerobic exercises. As you are aware, in modern times a n

Explain what is correction of hypovolemia, Explain what is Correction of Hy...

Explain what is Correction of Hypovolemia ? Intravenous fluids should be given to correct hypovolemia and optimize preload to the heart. This is particularly important in sept

Omni science valve-types of valves, Omni Science Valve :  Thi...

Omni Science Valve :  This is another type of tilting disc valve available from 1978. The cage is made of titanium and disc out of pyrolitic carbon. There have been a

Which are the cell organelles that participate in cell, Q. Which are the ce...

Q. Which are the cell organelles that participate in cell division and in the formation of cillia and flagella of some eukaryotic cells? The organelles that participate in the

Explain about the derived proteins, Explain about the Derived Proteins? ...

Explain about the Derived Proteins? These are not naturally taking place proteins and are obtained from simple proteins by the action of enzymes and chemical agents, heat, mech

What are some prophylactic measures for tapeworm infections, Q. What are so...

Q. What are some prophylactic measures for tapeworm infections? The major prophylactic measures against the taeniasis and the cysticercosis are not to ingest raw or badly cooke

Heterotrophs, Collect images of heterotrophs and make a Powerpoint Presenta...

Collect images of heterotrophs and make a Powerpoint Presentation on them

Phanerophytes - classes of life form, Phanerophytes - Classes of Life Form ...

Phanerophytes - Classes of Life Form The perennating buds in this case are present on erect, negatively geotropic shoots, much above the ground. These buds are naked or least

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