Author(s):

Showket A Dar, Gh. I Hassan, Bilal A Padder, Ab R Wani and Sajad H Parey

Abstract: Flowers exploit insects to achieve pollination; at the same time insects exploit flowers for food. Insects and flowers are a partnership. Each insect group has evolved different sets of mouthparts to exploit the food that flowers provide. From the insects' point of view collecting nectar or pollen is rather like fitting a key into a lock; the mouthparts of each species can only exploit flowers of a certain size and shape. This is why, to support insect diversity in our gardens, we need to plant a diversity of suitable flowers. It is definitely not a case of 'one size fits all'. While some insects are generalists and can exploit a wide range of flowers, others are specialists and are quite particular in their needs. In flowering plants, pollen grains germinate to form pollen tubes that transport male gametes (sperm cells) to the egg cell in the embryo sac during sexual reproduction. Pollen tube biology is complex, presenting parallels with axon guidance and moving cell systems in animals. Pollen tube cells elongate on an active extracellular matrix in the style, ultimately guided by embryo sac signals. A recognition system occurs between pollen grains and the stigma. Complex mechanisms act to precisely target the sperm cells into the embryo sac. These events initiate double fertilization in which the two sperm cells fuse to produce products.

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