NO EVIDENCE FOR SELECTIVE SEED MATURATION IN ANCHUSA-OFFICINALIS (BORAGINACEAE)

The potential for selective seed maturation based on embryo vigour ("female choice') was examined in Anchusa officinalis. Removing 2 ovules in the 4-ovulate flower before growth of the embryos has no effect on the remaining ovule positions in terms of seed maturation. The maturation pattern is thus determined within 1-2 days after flowering, and the decision as to whether or not a seed is matured is unlikely to be based on characters associated with embryo growth. At least some of the non-developed ovules may reflect the presumably post-zygotic self-incompability system of Anchusa. Seeds developed from the remaining ovules after the treatment were lighter than seeds produced by the control flowers, but this was probably a direct effect of the removal procedure rather than a result of maturation of seeds of low genetic quality. In 2 seeded flowers, the chance that a seed matured was higher than expected if the other seed was in one of the adjacent ovule positions and lower if it was in the opposite position. This may decrease the ability for the plants to favour only high quality zygotes since these may not always be associated with the best ovule positions. -Author