DIFFERENTIATED CADMIUM UPTAKE AND ITS EFFECT ON THE PHYSIOLOGY OF SIX CACAO GENOTYPES (Theobroma cacao L.) IN SAN RAMÓN, CENTRAL PERUVIAN JUNGLE

Abstract

Background. Cacao is an important source of income, especially for small farmers in developing countries. However, its commercialization, and consequently its production, is threatened by the high levels of cadmium (Cd+2) in grains. Objective. This work was carried out with the objective of determining the differentiated uptake of six cacao genotypes in San Ramón, central Peruvian jungle. Methodology. The treatments consisted of the combination of different doses Cd+2 (0, 50, 100 and 150 ppm) with the genotypes CCN-51, ICS-60, ICS-95, POUND-7 and VRAE-99. Results. The results indicate that POUND 7 absorbed a greater amount of Cd+2 concentrated mainly in the root, while CCN-51 concentrated it mainly in the aerial tissues. In VRAE-99, a significant drop in stem height and diameter was observed, especially at the 150 ppm dose. This genotype was shown to be more sensitive to this metal at high doses (150 ppm) and decreased its photosynthetic rate and its efficiency in the use of water, which was confirmed by the increase in the internal carbon content. Implications. In general, it was found that POUND-7 is a promising genotype that can potentially be used as a rootstock because it is capable of accumulating Cd+2 mainly in the roots. Conclusion. Although cacao is considered a Cd+2 accumulator plant, this heavy metal can negatively affect the physiology of the plant as in the case of VRAE-99. Further studies are suggested to better understand how Cd+2 affects cacao physiology.

Keywords

• cacao
• cadmio
• genotipo
• portainjerto.