pollenkorrel

Pollenkorrel, or pollen grain, is the microscopic male gametophytic unit produced by the anthers of seed plants. It carries the male gametes required for fertilization and plays a key role in plant reproduction. The size, shape, and surface pattern of pollenkorrels vary widely between species, but most are optimized for their specific pollination mode, whether wind, water, or animal vectors.

Anatomically, a pollenkorrel consists of an outer wall called the exine and an inner wall called the intine. The exine is usually highly resistant due to its composition of sporopollenin, and it often displays characteristic sculpturing and apertures that aid in identifying taxa. The intine lies beneath the exine and surrounds the cytoplasm, which contains nutrients for the developing gametophyte. In many flowering plants, a mature pollen grain contains a vegetative cell and a generative cell, the latter of which divides to form the two sperm cells used in double fertilization.

Development begins in the microsporangia (anthers) with microsporocytes undergoing meiosis to produce haploid microspores, which then divide by mitosis to yield the two-cell or three-cell pollen grain stage. Upon reaching a compatible stigma, pollen grains hydrate and germinate, forming a pollen tube that penetrates the style and delivers sperm cells to the ovule.

Pollenkorrel are central to palynology, ecology, archaeology, and forensic science. Their morphological features enable species and lineage identification, while fossil pollen provides insights into past climates and vegetation. They also have relevance in allergology, where pollen exposure affects human health.