Flowers and the Plant Breeder

The work required of the plant breeder depends on the type of cross desired and on the flower structure of the species.

Quiz

Question

What kind of plant would require the most flower manipulation to control a cross pollination?

Looks Good! Correct: Perfect flowers will have the pistil and stamen together in the same structure. Sometimes, very delicate manipulation is required to remove the stamens and leave the pistil intact.
Question

What kind of plant would require the least flower manipulation to control a cross pollination?

Looks Good! Correct: Dioecious plants need no manipulation other than selecting and isolating the desired male and female plants and growing them together.
Question

In which of the perfect flowers below would it be easier to make a controlled cross?

Looks Good! Correct: Lilies have large flowers and the stamens would be easy to remove. The stamen and pistil are small in Achillea.

Lily plant with big flowers. Image by Don Lee

Achillea plant with small bundles of flowers. Image by Kim Todd

Monoecious plants do not require flower manipulation that involves removing a stamen but may require flower protection. The female flower can be protected from pollen by covering it before it’s stigma is receptive. Pollen can be collected from a male flower and introduced to the covered female flower.

Bagging a tassel to capture pollen. Image by Joel Stuthman

Artificial pollination accomplished through dumping harvested pollen directly onto the silks of an corn ear. Image by Joel Stuthman

These crossing operations require the plant breeder to use the proper tools and timing.

Here's the Making Crosses animation.

Dioecious plants require the least flower manipulation. For example, if female plants are grown in a proximity to only one type of male, all offspring produced on that female are the result of pollen from the same male. Controlling crosses can be as simple as deciding which plants to put in the same greenhouse or which plants to place next to each other in the field.