Coffea arabica rootstock resistant to Meloidogyne paranaensis nematodes

Abstract

Meloidogyne paranaensis is a species of root-knot nematode that affects coffee (Coffea arabica L.) tree growth by causing severe damages to the plant root. This study evaluated the agronomic performance of Coffea arabica progenies in an M. paranaensis-infested field and assessed the compatibility of resistant C. arabica genotype 28-I-4 (GEN28) as rootstock for susceptible cultivars. Experiment 1: under field conditions, six progenies were analyzed; the controls were ‘IPR100’ as resistant and ‘Catuaí Vermelho IAC 144’ (CtV144) as susceptible. Experiment 2: under greenhouse conditions, combinations of grafts and rootstocks between susceptible CtV144 and GEN28 were evaluated regarding their resistance to M. paranaensis alongside their noninoculated counterparts. For this, M. paranaensis reproduction factor (RF), total population of the nematode per gram of root system, growth parameters, gas exchange, and water potential (ψpd) were evaluated. In Experiment 1, resistant C. arabica progenies were more vigorous, productive, and showed a population of M. paranaensis threefold-times lower than that observed in roots of susceptible CtV144. Among the resistant progenies selected in the field experiment, GEN28 was chosen for physiological compatibility study with the traditional cultivar CtV144. In Experiment 2, the CtV144 grafted onto GEN28 led to resistance to M. paranaensis, as well as a higher leaf area and ψpd as compared with nongrafted CtV144. Therefore, the GEN28 holds suitable characteristics to be used as a new Coffea arabica rootstock applied to production of resistant seedlings to Meloidogyne paranaensis nematodes. This technology represents an alternative to keep up coffee activity in infested areas.