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 the events in pollen-pistil interaction with its significance. Pollen-Pistil Interaction: Pollen grains are deposited on the stigma either due to closeness of the anthers to the stigma or by pollinating agents (biotic or abiotic). This unique feature brings about pollen-pistil interaction between the male gametophyte, the pollen grains, with the massive sporophytic tissue. [...]
The following points highlight the four main methods of air sampling. The methods are: 1. Gravity Sedimentation Methods 2. Inertial Methods 3. Filtration 4. Precipitation. 1. Gravity Sedimentation Methods: a. Sedimentation from still air: Alvarez and Castro (1952) constructed a simple box for the study of airborne fungi, has two hinged slides and a covered tray at the bottom for [...]