Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Sporophytic Incompatibility
The recognition and rejection reactions in a SSI system occur on the stigma surface, placing barriers for pollen germination or penetration of pollen tube into the stigma. Thus the pollen grains either fail to germinate or the small tube they put out is inhibited by callose deposition at the tip. The papillae at the stigma also develop a lenticular callose plug within 10 min after pollination. Infact, in incompatible cases, inhibition of varying degrees operates at every level starting from pollen adhesion, hydration, germination and tube entry into the stigma. In some plants stigma is covered with a cuticular layer such that the incompatible pollen tube fails to penetrate.
Various studies have proved the necessity of enzyme cutinase in eroding the cuticle. This enzyme is activated only by the compatible cases. Incompatible stigmas may lack copious exudate, but dry stigmas have a hydrated layer called pellicle over the cuticle. This pellicle consists of a lipid layer where a mosaic of proteins floats. The pellicle probably originates by the protrusion on the surface of the papillae through discontinuities in the cuticle. As soon as pollen is received by the stigmatic surface the papillate cells exude moisture. The incompatibility is the result of interaction between protein fractions of exine and stigma.
Terrestrial and Aquatic Ecosystem What is common between a terrestrial and an aquatic ecosystem. Both have similar type of trophic structure. They possess an autotrophic layer
What is heterophagic intracellular digestion? How is this process accomplished? Heterophagic intracellular digestion is the breaking into minor substances of external substance
List the short-term and long-term effects of forest destruction (a) on hillsides, (b) in the tropics. (a) Deforestation on hillsides exposes the soil to erosion by rain and l
Explain the Swab Method? Swab method is the oldest and widely used method in food and dairy industry and was developed by W.A. Manheimer and T. Ybanez in 1917. A sterile cotton
Placenta - Human Development We had said previous in the unit that in the second week of development a primitive uteroplacental circulation is established. Early in this stage
Identifications of a deficit by neuropsychological tests Ideometric approach and psychometric approach are the two methods that are used in the identification of deficits by ne
Q. How is the nervous system of nematodes organized? Where are the neural chords located in their body? Roundworms have a ganglial nervous system with an anterior neural ring r
ASPIRIN - It is acetylsalicyclic acid (C 6 H 4 (OCOCH) 3 CH 3 ). It changes in salicyclic acid in body. It is analgesic, antipyratic (fever reducing), anti inflamma
Q. What are the other names by which erythrocytes are known? What is the function of these cells? Erythrocytes are also known as red blood cells (RBCs) or red corpuscles Red bl
What is the thermopenetration concept? The pasteurization of products packed in glass containers leads to a problem of a specific nature, which is referred to as 'thermopenetra
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd