Biometrical, biological, biochemical and molecular characteristics of Meloidogyne incognita isolates and related species

• Published in: European journal of plant pathology Vol. 134; no. 4; pp. 671 - 684
• Main Authors: dos Santos, Marcilene Fernandes Almeida, Furlanetto, Cleber, Almeida, Maria Rita Alves, Carneiro, Marina Dechechi Gomes, Mota, Fabiane Castro, Gomes, Ana Cristina Meneses Mendes, Silveira, Natália Orrú Reis, Silva, Joelma Gardênia Pereira, Castagnone-Sereno, Philippe, Tigano, Myrian Silvana, Carneiro, Regina Maria Dechechi Gomes
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.12.2012; Springer Netherlands; Springer; Springer Nature B.V; Springer Verlag
• Subjects: Agriculture; Biochemistry; Biological and medical sciences; Biology; Biomedical and Life Sciences; Biometrics; Ecology; Environmental Sciences; esterase; Fundamental and applied biological sciences. Psychology; genetic markers; genetic variation; Life Sciences; malates; Meloidogyne; Meloidogyne incognita; microsatellite repeats; Molecular biology; Nematoda; phenotype; Phylogeny; Phytopathology. Animal pests. Plant and forest protection; Plant Pathology; Plant Sciences; Primers; Random amplified polymorphic DNA; random amplified polymorphic DNA technique; root-knot nematodes; stylets; Topology; Brazil; Molecular markers; Root-knot nematodes; Esterase phenotypes; Plant pathogen; Root; Enzyme; Esterases; Phenotype; Plant; Pest; Meloidogyne hispanica; Meloidogyne incognita; Helmintha; Hydrolases; Meloidogynidae; Isolate; Nemathelminthia; Invertebrata; Nematoda; SAO-PAULO; PARASITIZING COFFEE; POPULATIONS; IDENTIFICATION; BRAZIL; ENZYME PHENOTYPES; GENETIC DIVERSITY; SPP; SCAR-PCR; ROOT-KNOT NEMATODE
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-012-0018-1

Meloidogyne incognita is one of the most polyphagous species of root-knot nematodes occurring in Brazil and worldwide. Eight M. incognita isolates were studied, representing two enzymatic phenotypes (esterase and malate desydrogenase: I1/N1, I2/N1) and four cryptic Meloidogyne sp.1 (S2/N1) isolates, representing one cytological type (3n = 40–46). Three M. hispanica isolates (Hi3/N1, 2n = 32–36) and two of an atypical Meloidogyne sp.2 (S2a/N3, 3n = 40–44) were included in this study for comparison. All isolates were tested with three M. incognita-specific molecular markers. The primer pairs B06F/R, miF/R and incK14F/R amplified three species-specific fragments of 1,200 bp, 955 bp and 399 bp, respectively for M. incognita and Meloidogyne sp.1 isolates. No amplification occurred in the M. hispanica and Meloidogyne sp.2 isolates, except with primers miF/R (1,650 bp). The genetic variability of the Meloidogyne spp. isolates was evaluated, using RAPD and ISSR markers. The phylogenetic analyses revealed two strongly supported monophyletic clades: clade I, consisting of M. hispanica and the atypical Meloidogyne sp.2 isolates, and clade II, clustering together all M. incognita and the Meloidogyne sp.1 isolates. Considering the biometrical, cytological and molecular approaches, it was possible to conclude that the isolates with three enzymatic phenotypes (I1/N1, I2/N1 and S2/N1) presented the characteristics described for M. incognita. Some correlations were detected between the isozymatic phenotypes and the tree topology (S2a/N3, Hi3/N1, I1/N1, S2/N1), but no strict correlation could be observed for the phenotype I2/N1 and one isolate of S2/N1. Morphologically, the Msp.2 isolates differ from M. incognita and M. hispanica by the female stylet features presenting straight cone tip and round pear shaped knobs, posteriorly sloping. The results of this study suggested that the Msp.2 isolates with phenotypes S2aN3 belong to a new or an unidentified species closely related to M. hispanica.