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

Growth curve, GROWTH CURVE - Sigmoid curve or stretched 'S' shap...

GROWTH CURVE - Sigmoid curve or stretched 'S' shaped curve is obtained showing - a - lag phase                              b - log phase c - in flaxion p

Genetics , Genetics Genetics is the study of heredity. It is an ancien...

Genetics Genetics is the study of heredity. It is an ancient discipline. At least 4000 years ago, in Sumeria, Egypt and other parts of the world, farmers recognized that they

What is life threatening haemorrhage, What is Life threatening haemorrhage ...

What is Life threatening haemorrhage Life threatening haemorrhage has been reported when a drill perforates the sublingual region of the mandible and injures the sublingual arte

What is triacylglycerol, What is triacylglycerol There are 3 hydroxyl ...

What is triacylglycerol There are 3 hydroxyl groups in a glycerol molecule. If all the three groups are forming ester  linkage with fatty acids, the resulting compound is call

Explain pancreatitis, Explain Pancreatitis Pancreatitis :- Inflammati...

Explain Pancreatitis Pancreatitis :- Inflammation of the pancreas.

What are the changes in the blood count, Many disease states are heralded b...

Many disease states are heralded by changes in the blood count Leukocytosis can be a sign of infection. Thrombocytopenia can result from drug toxicity. Pancytopenia is ge

How will consuming fewer than 1, How would consuming fewer than 1,200 kcalo...

How would consuming fewer than 1,200 kcalories per day impact metabolism.

Lipid digestion, Lipid Digestion Digestion of fats is also similar in...

Lipid Digestion Digestion of fats is also similar in both invertebrates and vertebrates. Lipases are the - enzymes that hydrolyse fats. A single lipase can catalyse many step

What is prostaglandins , Prostaglandins and the structurally associated mol...

Prostaglandins and the structurally associated molecules prostacyclins, leukotrienes and thromboxanes, are called as eicosanoids because they having 20 carbon atoms. These hormones

Respiration, abnormal lung volumes and capacities

abnormal lung volumes and capacities

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