Hybridisation

A hybrid is a cross between two different plants, which are usually two plants within the same species, but can be between two different species or genera. Hybrids can occur in nature by natural cross-pollination between plants, but here we will look at the artificial hybridsation of plants to produce a new form.

In artificial hybridisation two parent plants are chosen, each of which has required characteristics. The flowers of the plant designated to be the ’seed’ (mother) plant have their stamen removed with tweezers as soon as they appear (generally this is before the plant is fully open) to prevent the flower self-pollinating. The petals are also removed to allow ease of access to the stigma. The seed plant flower is then protected from other pollen (eg by covering with a muslin bag or by keeping it in isolation) for 24-48 hours until the stigma becomes ripe and sticky. The pollen from the designated ‘pollen’ (father) plant is then picked up on a fine brush and brushed against the stigma of the seed plant. Label the seed plant with the name of the pollen plant and continue to protect it from other pollen until the seed forms. Then collect the seed and sow. The first generation grown from the hybridisation is known as ‘F1′ (First Filial). Plants bred from F1 plants are called F2, and so on.

With water plants, the pollen is transferred into the liquid in the centre of a seed plant flower that is about to open. The plant is then covered to prevent further pollen reaching it.

Many plants are easy for the amateur gardener to hybridise at home, including chrysanthemums, hostas, dahlias, irises, roses, tulips and sweet peas. If you want to experiment, then make sure you have an aim in mind (eg to produce a large flowered, red flowered dahlia) and use parent plants which each have some of the characteristics you require. Use plants which already yield a good number of fruits and seeds. Then play around with hybridising them, each time selecting the best plants from each generation and breeding from them (potentially by crossing them back with the parents – incest isn’t an issue in the plant world!).