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

Safety measures in the administration of drugs, SAFETY MEASURES IN THE ADMI...

SAFETY MEASURES IN THE ADMINISTRATION OF DRUGS It is essential to revise the five "Rights" before administration of medication to the paediatric group. These as you know are:

Development of ovule, Development of Ovule The ovule develops from a s...

Development of Ovule The ovule develops from a specialised region of the ovary - the placenta. Initially it appears as a small mound on the placenta, and is composed of homoge

Digestive system - liver, LIVE R (HEPAR) - Largest gland of body. W...

LIVE R (HEPAR) - Largest gland of body. Weighing 1.6 kg. Form 1/40 of the body weight. Bio-chemical laboratory. Bussiest part in whole river of life. Dark reddish brown

Calf diptheria, Calf diptheria The disease is a serious one usually affect...

Calf diptheria The disease is a serious one usually affecting calves up to 2 years of age. The lesions are confined to larynx and pharynx, and consist of well-defined areas of nec

Name the two groups of nephrons, Name the two groups of nephrons on the bas...

Name the two groups of nephrons on the basis of their position in the kidney. How are they different from each other? a) How is the halophyte Rhizophora adapted to survive in i

Define phase of the cell cycle, Q. Generally which phase of the cell cycle ...

Q. Generally which phase of the cell cycle has longer duration? The mitotic phase has quite a shorter length and the interphase comprises approximately 4/5 of the cell cycle.

Lampbrush chromosomes, LAMPBRUS H CHROMOSOMES Discovered by Rucker...

LAMPBRUS H CHROMOSOMES Discovered by Ruckert . Lampbrush Chromosomes were seen in Oocytes of several different animals like shark, amphibians, reptiles and birds. (Most

Dietary fats required for dyslipidemia, Q. Dietary Fats required for dyslip...

Q. Dietary Fats required for dyslipidemia? Dietary Fats: There is a consistent support for the hypothesis that both the quantity and quality of fat are directly associated with

What are the major cells of which poriferans are made, Q What are the major...

Q What are the major cells of which poriferans are made? Sponges have their external wall covered by flat cells called pinacocytes and having pores well-delimited by special ce

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