INFLUENCE OF LIGHT ON ASSIMILATE PARTITIONING IN WHITE CLOVER (TRIFOLIUM-REPENS L)

In order to identify factors which might contribute to the premature abortion of young inflorescences of white clover Trifolium repens L. in low irradiances, a study was made of the possible role of limiting photosynthetic assimilates to the developing inflorescence. The relationship between the irradiance and distribution pattern of assimilates in the clover plant under different irradiances was determined. Besides driving the photosynthetic supply of sucrose, light seems to play an indirect role in controlling partitioning of photoassimilates. Under low irradiance, the growing tip of the shoot and roots were major sinks and negligible amounts of C-14-labelled assimilates were supplied to the inflorescence. In medium and high irradiances, the inflorescence competes for assimilates with stolon apex and roots.