Resistance of Malpighia emarginata DC. Genotypes to Meloidogyne enterolobii Parasitism

Abstract

Aims: Considering the inexistence of M. emarginata cultivars resistant to M. enterolobii available for cultivation, and the scarcity of information about the severity of its parasitism in M. emarginata, the present study investigated the response of genotypes from the active germplasm bank of Universidade Federal Rural de Pernambuco to M. enterolobii parasitism, aiming the selection of resistant genotypes for use as rootstocks for commercial varieties.
 Study Design: The experimental design was completely randomized, with 21 genotypes and one independent matrix (control), with six replicates each. The experimental unit was represented by one plant per plot.
 Place and Duration of Study: Department of Agronomy, Universidade Federal Rural de Pernambuco – UFRPE - Brazil between June 2013 and July 2014.
 Methods: In the experiment, completely randomized design was adopted, with 21 genotypes from the AGB and one as a control for susceptibility. The M. emarginata cuttings were inoculated with 10,000 nematode eggs, and after 150 days, they were evaluated for the following parameters: Egg mass index, gall index, reproduction factor, number of eggs per gram of root, number of eggs per root system.
 Results: Twenty out of the twenty-two genotypes analyzed were susceptible. The genotypes 021-CMF and 037-CMF were considered resistant. To our knowledge, this is the first identification of M. emarginata genotypes resistant to M. enterolobii.
 Conclusions: These results are of great importance for the breeding and cultivation of the species since these two genotypes can be indicated for use as rootstocks and for breeding programs aimed at transferring resistance to other cultivars with desirable production characteristics that are susceptible to the phytonematode.