developing fruits cover 3.jpg (515677 bytes)
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.