Diversidade genética de Coffea canephora usando parâmetros do sistema radicular

Abstract

Studies aimed at understanding the distribution of the root system of coffee plants are still little explored. The objective of this work was to know the distribution of the root system of a productive C. canephora population, to identify potentially promising genotypes under adverse conditions, as well as their genetic diversity based on the study of root traits. At the same time, the aimed was to verify if there is a correlation between the root characteristics and height of coffee plants. For this study, root monoliths at six soil depths from each of the 43 studied genotypes were collected at a standard distance of 30 cm towards the coffee planting line at six soil depths (0-10; 10-20; 20-30; 30-40; 40-50; 50-60 cm). The roots were washed, digitized and processed by the Safira program to quantify the surface area (mm² cm-³), length (mm cm-³), volume (mm cm-³) and diameter (mm cm-³). A randomized block design with four replications in a 6 x 43 double factorial scheme was used. The depth factor consisted of six levels and the genotype factor by 43 levels. Significant differences between genotypes and depths were observed for all variables analyzed.The highest concentration of roots occurred at the most superficial depths (0-20 cm). Genotypes 14, 25 and 31 stood out in the surface area, length, volume, and diameter in the deepest soil layers. There is a correlation between root characteristics and plant height, however, the observed correlation was weak. It was possible to estimate genetic diversit1y based on the root characteristics of coffee plants.