Export and Partitioning of ¹³C-labelled Photosynthates from a Treated Leaf of a Mother Cymbidium Plant or its Lead to Other Organs

Abstract

A leaf on a lead or the mother Cymbidium (mericlone of Cymbidium Walu ‘Green Heart’) plant was administered ¹³C. Subsequently, the export or translocation and partitioning of ¹³C-photosynthates from those leaves to the other organs on the same plant were examined. When ¹³C were applied to a leaf of one of two leads, virtually ¹³C-photosynthates translocation to the mother plant began on the 9th day, reaching the maximum rate on the 12th day. However, on the 12th day, 51.2% of the photosynthate still remained in the treated leaf, whereas 14.2% was partitioned to the roots of mother plant and 19.4% to the leaves of other lead. When ¹³C was administered to a leaf on a mother plant, a high concentration of ¹³C appeared in the psudobulbs of the lead and in roots of the mother plant. The partitioning pattern of ¹³C were: ¹³C-fed leaf, 16.3%; mother plant pseudobulb, 4.1%, mother plant roots, 42.2% (making a total of 62.6% to the mother plant); lead leaves, 34.2%; and lead pseudobulbs, 3.2%.