Biochemical characterization of leaves in Theobroma cacao clones and its relation with trichomes

Abstract

Theobroma cacao L. is a crop of major importance for their potential applications in pharmacy and agriculture. It contains metabolites that are of great interest for its natural biological functions in plant response to different types of stress, both biotic and abiotic. The presence, type and concentration of both primary and secondary metabolites may vary depending on the genotype analyzed and these compounds can accumulate in the architecture associated structures such as leaf trichomes. The aim of this study was to characterize 26 clones of the germplasm bank of Padrón, INIA-Miranda, Miranda State, Venezuela and study the relationship between biochemical indicators assessed and the number of trichomes. The content of phenolic compounds, soluble protein, free proline, total carbohydrates, lignins, the number of trichomes and the relationship between all traits was determined. The results showed that in the two dimensional space explained 46.68% of the variability, five homogeneous groups were defined: 10 clones were associated with the maximum gradient of proline, total carbohydrate and lignin content. Nine clones were associated with high content of phenols and a group of seven clones with the highest number of trichomes on leaves. It was found that the number of trichomes was not related to the concentration of phenolic compounds. The clones of Forastero cocoa type showed higher concentration of total phenols and carbohydrates, meanwhile the Trinitario type presented higher concentration of proteins and prolina.

Keywords

• análisis de componentes principales
• fenoles
• prolina
• proteínas
• carbohidratos
• principal components analysis
• phenols
• proline
• proteins
• carbohydrates