Pollen wall development may be considered under exine and intine growth phases. 1. Exine Growth Phase: After meiosis of microsporocyte (microspore mother cells) the tetrads of haploid microspores are enveloped by a callosic wall. The callose wall can be detected around the microspore mother cells during initiation of meiosis (Fig. 2.1a and 2.2a). It forms a layer between the cytoplasm [...]
In this article we will discuss about the methods and significance of pollen storage in plants. Systematic research on pollen storage started at the end of the 19th century. There is large number of crop species, including vegetables, fibre and fruit crops, forage and cereals, for which pollen storage strategies are desirable. Genetic conservation through pollen storage is desirable for [...]
In this article we will discuss about:- 1. Distribution of Sporopollenin 2. Chemistry of Sporopollenin 3. Production and Deposition 4. Functions. Distribution of Sporopollenin: It was first observed and named as "sporonin" by John (1814) and latter characterized by Berzelius (1830). Fossil green algae dating back to Devonian period have been shown to contain sporopollenin. The oldest sporopolleninous acritarchs occur [...]