Potencial morfofisiológico de porta enxerto de Coffea arabica resistente a Meloidogyne paranaensis

Abstract

Bearing in mind that the area contaminated by Meloidogyne paranaensis has been increasing in the main coffee growing regions, and that it is an extremely harmful nematode to coffee farming, arises the need to investigate effective, low-cost and short-term management techniques. Facing that, the aim of this work is to evaluate the genotype potential of M.paranaensis resistant Coffea arabica for use as rootstock with highly susceptible cultivars, such as IAC 144 Catuaí Vermelho. The experiment was conducted in a greenhouse in a randomized block design in a factorial scheme of 6 grafting combinations which were, ungrafted IAC 144 Catuaí Vermelho and genotype 28 seedlings, self-grafting of these materials, Catuaí grafting in genotype 28 and genotype 28 grafted in Catuaí. Two levels of M.paranaensis nematode were applied in this grafting scheme, namely presence and absence through 8 replications, each plot consisting of one plant per pot. Growth, gas exchange, water potential and nematode replication factor (RF) were evaluated. It was found that at 0, 65, 101, 147 and 250 days after inoculation (DAI), resistant genotype seedlings used as rootstock presented no change in growth, photosynthetic rate and water potential when inoculated. In addition, these seedlings demonstrated low nematode replication factor, represented by a value lower than 10% of the susceptible control's replication factor. It follows that genotype 28 rootstocks presented potential for use as rootstock for Catuaí, producing seedling which are highly resistant to M. paranaensis.