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.
Define some Usual Doubts of Children related to Food? Before embarking yourself to go through this unit, here is an activity for you to perform, Talk to 2-3 school' boys and gi
whats ur clear definition of virus
2. Describe the respiratory organs and mechanism of respiration in pila.
Problem 1: How do you differentiate between a dossier and a submission document? Define dossier Define submission document differentiate between a dossier and a
Determine about the Psychological tests The construct of attention has been found to comprise several interrelated elements that the paediatric neuropsychologist can consider i
What is xaxim? Most pteridophytes have subterraneous stems similar to the substrate called as rhizomes. Xaxim is a kind of pteridophyte with an aerial stem in generally perpend
basis of genetic transplantation
Explain some Characteristic Features of Mucor? 1. Stolons characteristics of Rhizopus are absent in Mucor. The aerial mycelium in Mucor consists of branched hyphae, which grow
topics for zoology assignment for plus one
Describe DNA replication in details? Replication : DNA replicates itself by first breaking the hydrogen bonds between the nitrogen base pairs, and "unzips" itself into two s
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd