2.1.3. Testing for geitonogamy (selfing within the same plant)

Some flower species do not set fruits/seeds when self-pollinated but do so when receiving pollen from other flowers of the same plant (geitonogamy). This can happen between perfect (hermaphroditic) flowers, but it is obligatory in autogamous plants which are monoecious (unisexual male and female flowers on the same plant). This test will tell us whether the flower can set seeds and fruits when receiving pollen from other flowers of the same plant. This is important information because honey bees tend to explore many flowers per plant before moving to other plants, and this behaviour favours geitonogamy.

  1. Repeat the procedures for testing for autogamy (section 2.1.2.), but replace the treatment using the flower’s own pollen for a treatment using pollen from another flower on the same plant.
  2. Conclusions are similar to those above for testing autogamy (section 2.1.2.), except that if fruits or seeds developed from the geitonogamy treatment it means that the plant sets when pollen is transferred between its own flowers. The proportion of fruit- or seed-set obtained from the geitonogamy treatment in relation to the control treatment will tell the extent to which the plant is responsive to this mode of mating system.