Root system of Coffea canephora cv. Robusta genotypes cultivated in the Brazilian Amazon

Abstract

The root system distribution of coffee, especially Coffea canephora cv. Robusta, remains poorly characterized. The aim of this study were: (i) to analyze the distribution of the root system in various genotypes of C. canephora cv. Robusta cultivated in the Amazon region; (ii) to evaluate genetic variability based on root traits; and (iii) to test the correlation between root traits, aboveground part, and production capacity. Roots were collected up to a depth of 60 cm and 30 cm away from the stems. The roots were washed, scanned, and processed to quantify root volume (mm3 cm−3), surface area (mm2 cm−3), diameter (mm), and length (mm cm−3). The variations in root systems reveled phenotypic variability among different genotypes of C. canephora cv. Robusta. Most roots were concentrated in the surface layer of the soil (0–30 cm), with LB015 standing out. At a depth of 50–60 cm, AS10, AS4, A106, and GJ08 had more roots than other genotypes, suggesting a promising capacity to avoid drought. There were significant negative correlations between root traits, aboveground part, and production capacity. This study provides valuable information for the selection of genotypes with desirable root traits for different environmental conditions, contributing to the improvement of management practices and breeding programs for Robusta coffee.