Diversity of Meloidogyne exigua (Tylenchida: Meloidogynidae) populations from coffee and rubber tree

Abstract

Isozymes (esterase and malate dehydrogenase), SCAR and RAPD-PCR were studied in 15 populations of three races of Meloidogyne exigua collected in coffee-producing areas in Brazil, Bolivia and Costa Rica and one population from rubber tree plantations in Brazil. This study revealed four esterase phenotypes (E1, E2, E2a, E3) and three malate dehydrogenase phenotypes (N1, N1a, N2) for M. exigua populations. The most common multi-enzyme phenotype was E2N1. The enzymatic phenotypes do not separate M. exigua races. Sixteen populations of M. exigua were tested in Multiplex PCR using SCAR primers ex-D15F/R that allowed the identification of all M. exigua populations. Phylogenetic analyses showed high intraspecific polymorphism (25.9-59.6%) for all M. exigua studied. However, all populations clustered together with 100% bootstrap support, thereby demonstrating the consistency of species identification. In general, no correlation was found between enzymatic profile, race and genetic polymorphism of the studied populations.

Additional information on an atypical population of Meloidogyne exigua Göldi, 1887 (Tylenchida: Meloidogynidae) parasitising rubber tree in Brazil

“…Using the RAPD pattern we detected high polymorphism (43.1-57.8%) among populations from coffee and that from rubber tree (Muniz et al, 2008). Phylogenetic analyses showed that the latter population clustered together with 15 M. exigua populations from coffee with 100% bootstrap support, but formed a distinct branch (Muniz et al, 2008).…”

“…One secondary band (Rm = 1.6) was observed in the population from rubber tree, but other secondary bands were also observed in some populations from coffee (see Muniz et al, 2008).…”

“…Molecular analysis using SCAR markers of the population from rubber tree resulted in a fragment of 562 bp, specifically amplified in M. exigua from coffee (Randig et al, 2002;Muniz et al, 2008). Using the RAPD pattern we detected high polymorphism (43.1-57.8%) among populations from coffee and that from rubber tree (Muniz et al, 2008).…”

“…Using the RAPD pattern we detected high polymorphism (43.1-57.8%) among populations from coffee and that from rubber tree (Muniz et al, 2008). Phylogenetic analyses showed that the latter population clustered together with 15 M. exigua populations from coffee with 100% bootstrap support, but formed a distinct branch (Muniz et al, 2008). Furthermore, our cytological study also indicated the occurrence of meiotic parthenogenesis (n = 18) in M. exigua race 3, the same type of reproduction that occurs in M. exigua from coffee (Triantaphyllou, 1985a).…”

Desenvolvimento de mudas de cultivares de café arábica enxertadas sobre Apoatã IAC 2258

“…Nos últimos anos, extensivos levantamentos e estudos têm detectado um vasto número de espécies de nematóides capazes de parasitar as raízes de cafeeiro (CARNEIRO et al, 2008, MUNIZ et al, 2008) e a situação pode diferir grandemente de uma região para outra.…”