Abstract

The aim of the present work was to identify the degree of drought tolerance in different elite genotypes of Coffea canephora P. var. Robusta. The study was conducted from 2013 to 2015 in Tuxtla Chico, Chiapas, Mexico. Twenty plants from each genotype were used (INIFAP P9, INIFAP P4, INIFAP P5, INIFAP P7, INIFAP P8), except for INIFAP P9 with twelve; a group with half of the plants of each genotype was under field capacity (FC) and the other half under permanent wilting point (PWP). Several morphological and physiological variables were considered at the end of the stress stage and after recovery irrigation, such as growth parameters, relative water content, proline accumulation, stomatal index and density and index of drought tolerance. C. canephora genotypes presented different degrees of tolerance to water deficit, and may have activated several pathways to tolerate drought, according to a decrease in relative water content and increase in proline content. Our results suggest that the most tolerant genotype was INIFAP P5 according to the total number of leaves, relative growth rate, and total number of pairs of plagiotropic branches and nodes; while INIFAP P4 was identified as one of the most susceptible according to relative growth rate and total number of nodes. 

Keywords: water deficit, tolerance index, field capacity.