|As fathers go, plants are the pits! With help of wind, insect,
or bird, most cast their pollen indiscriminately into the environment and leave
child-rearing entirely to mom. So you wonder why mom would allow dad to have any influence
at all on junior, particularly on mom's own tissues in the fruit? It happens.
Just as pollen parent affects defense of offspring in
parsnips, pollen parents also influence photosynthesis of the fruits that contain
their offspring. Up until a fruit ripens and turns brown, it is green and
photosynthetic. We now know through the use chlorophyll fluorescence imaging that
rates of gross photosythesis in a fruit (visualized in the red false-color image
above) does indeed depend on who fathered the residing offspring. The implications
of this phenomenon are potentially the same as for pollen effects on defense--kin
conflict. Offspring compete for resources--in this case, presumably materials for
the machinery of photosynthesis--in hopes of getting a leg up on a half-sibling.