Morphological characteristics of pollen grains have been categorised into different groups: 1. Pollen Units 2. Polarity 3. Symmetry 4. Shape 5. Size 6. Apertures 7. Sub-Divisions of the Pollen Surface 8. Sporoderm Stratification 9. Exine Ornamentation 10. 'LO' Analysis. Characteristic # 1. Pollen Units: The pollen grains are produced within the anther of the flower. Pollen mother cells originate from [...]
In this article we will discuss about:- 1. Meaning of Self-Incompatibility 2. Molecular Basis 3. Determinants 4. Significance. Meaning of Self-Incompatibility: Self-incompatibility or intraspecific incompatibility is a well-designed genetic mechanism by which certain plants recognize and reject their own pollen thus forcing outbreeding. It is defined as "inability of the plant producing functional gametes to set seed upon self-pollination",. Lundqvist [...]
In this article we will discuss about:- 1. Morphology of Orbicules 2. Development of Orbicules 3. Functions. Ubisch bodies were first discovered by Rosanoff (1865) in close association with the tapetum. Kosmath (1927) suggested that these bodies should be called "Ubisch granules" while Erdtman (1961) proposed the term "orbicules". Morphology of Orbicules: Orbicules are small and generally spherical structures (2-5 [...]