Consumption and utilization of assimilates in petals of 'Cox' apple flowers

摘要

Within the flower the petals were a strong sink attracting assimilates. They played an important role in attracting photosynthates towards the flower from the photosynthesizing sites, and the capacity of the flower to mobilise assimilates was greatly decreased when the petals were removed. Application of growth-promoting hormones could restore the capacity of petalless flowers to mobilize assimilates. Remobilization of assimilates deposited in the petals had taken place before the petals were shed, but the extent was limited. Pollination and fertilization increased the remobilization, but the major porfion of the assimilates deposited in petals and was lost in the event of petal fall. Therefore, on overall balance the petals were assimilate consuming organs rather than temporary assimilate storage sites.