ABSTRACT
In seed plants, pollination is a prerequisite for fruit- and seed-development and is the basis of genetic exchange between plants and recombination within plants. Flowering plants have evolved an amazing array of adaptations to achieve pollination. Many species produce both chasmogamous and cleistogamous flowers depending on environmental conditions, especially temperature and light duration. Pollination is a critical factor for sustainable agriculture and for commercial production of hybrid seeds. A breeding system includes pollination mechanisms and pollen movements. Pollen is generally presented in situ on the dehisced anthers for transfer by pollinating agents. Pollen is deposited on a specific floral structure, termed the pollen presenter, from which pollen is distributed for cross-pollination. Anemophilous plants produce an enormous amount of pollen; this is achieved by an increase in size of anthers or in number of stamens per flower, and in species which bear unisexual flowers, the number of male flowers per plant is increased.
