Plant Breeding – Tomato

A scanned red tomato, along with leaves and fl...

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The tomato has a perfect flower, with male and female organs both within the same blossom . The sex organs are easy to tell apart and therefore it is relatively easy to cross tomatoes.

For this experiment, choose tomatoes with two different fruit colors, such as red and yellow. If the tomatoes are pure, variations in color will show up in the F2generation. Along with color variations, there will probably be changes in fruit shape and other plant characteristics.


  1. Plant the seed or young plants and label the rows so that you will know which will bear red fruit and which will bear yellow fruit. The tomato produces flowers for several weeks, so there will be no difficulty in having pollen and seed parents ready at the same time.
  2. As soon as the flowers that will serve as seed parents begin to open, the plant should be emasculated. The stamens are fused to the petals, so all you need to do to emasculate the plant is to pull out the petals.
  3. After you remove the stamens from the seed parents, cover the flowers securely.
  4. The pollen parents that you wish to use should be in the same stage of opening as the seed parents. Cover the pollen parents at the same time that you cover the seed parents.
  5. As soon as the pollen-parent flower is completely open, remove one of its stamens with scissors or tweezers. Remove the bag from the seed parent and gently brush the anther across the stigma.
  6. Replace the bag that was removed from the seed-parent flower.
  7. Label the flower that was pollinated and enter the cross in your record book.