TRACKING CARBON FROM PHOTOSYNTHESIS TO LATEX WITH 13C FIELD LABELLING EXPERIMENT
DOI:
https://doi.org/10.22302/ppk.procirc2017.v1i1.484Abstrak
Rubber trees must mobilize a huge amount of carbon to regenerate the latex after tapping. Knowing the C sources and pathways towards latex will help managing tapping systems. We labelled 4y-old tapped rubber trees with 13CO2 and analyzed 13C content in leaves, phloem, wood and latex during one year to determine the dynamics of C allocation. The peak of 13C in latex 10-15 days after labelling in June indicated that newly assimilated C was mixed in a pool of reserves before being used to regenerate latex. The earlier (6-8 days) and much higher peak in October showed that when the regeneration metabolism was well established the transfer of recent assimilates was faster. In both cases 13C was recovered more than 40 days after labelling, demonstrating the contribution of reserves. 13C recovery in soluble sugars and quebrachitol, an important osmoticum, are followed-up to specify their dynamics.
Keywords: carbon allocation, carbohydrates, latex regeneration, reserves, stable isotopes.