Use of physiological characteristics to identify genotypes of arabic coffee tolerant to Meloidogyne paranaensis

Abstract

This work aimed to evaluate on use of physiological traits to identify genotypes of arabic coffee tolerant to Meloidogyne paranaensis when cropped in areas subjected to water deficits. The experiment was performed in field conditions with two genotypes: 16(MG 0179-1R1) and 28(0179-3 MGR1) and two cultivars: IPR-100 (resistant control) and Mundo Novo IAC379-19 (susceptible control) in a randomized block design with five replicates. The evaluated characteristics were: nematode population at the root, production, crown diameter, plant height, vegetative vigor, predawn leaf water potential (ψam), net photosynthesis (A), stomatal conductance (gs), transpiration (E), leaf temperature (TF), water use efficiency (WUE) and chlorophyll a fluorescence parameters. Genotypes 16, 28 and IPR100 showed higher vegetative growth and higher production than cv. Mundo Novo, especially the genotype 28. The leaf water potential was higher in genotypes16, 28 and IPR-100 compared to cv. Mundo Novo. However, the genotypes showed no differences in gas exchanges. According to the chlorophyll a fluorescence parameters, genotype 28 showed better photochemical performance and acclimation to water deficit. The physiological characteristics identify tolerant genotypes to Meloidogyne paranaensis when cropped in areas subjected to water deficits, especially for the analysis of chlorophyll fluorescence, since it can be used in large-scale assessments.