CEPAVE   05420
CENTRO DE ESTUDIOS PARASITOLOGICOS Y DE VECTORES
Unidad Ejecutora - UE
artículos
Título:
First Report of Meloidogyne partityla Infecting Water Oak (Quercus nigra) in Florida, USA
Autor/es:
BRITO JANETE; MONTEIRO TSA; ACHINELLY , MARÍA F.,; SMITH T; DICKSON DW
Revista:
PLANT DISEASE
Editorial:
AMER PHYTOPATHOLOGICAL SOC
Referencias:
Año: 2016
ISSN:
0191-2917
Resumen:
The pecan root-knot nematode M. partityla was first reported infecting pecan seedlings in a nursery in 2005 and laurel oak (Quercus laurifolia) in 2009 in Florida. The infection of laurel oak was the first report of a plant host outside of the Junglandaceae family. In January 2009 and February 2015, roots of water oak (Quercus nigra) exhibiting large coalesced galls and egg masses resembling those induced by root-knot nematodes were found in two different home gardens, AlachuaCo., FL. Second-stage juveniles, female and male root-knot nematodes extracted from the oak roots were identified based on their morphology. In addition, females were subjected to polyacrylamide gel electrophoresis to identify their isozyme phenotypes. Key morphological features used were the perineal pattern of females, the swollen and clear longitudinalgrooves in rectum of J2, and thickened region between the stylet cone and stylet shaft of males. The isozyme phenotypes (EST=Mp3;MDH=N1a) were consistent with that previously reported for M. partityla. Identification was further confirmedusing molecular analyses of the mitochondrial DNA (mtDNA) region between CO II and 16S; 18S rDNA; and rDNA ITS, a region containing ITS1, 5.8S and part of ITS2. DNA extracted from M. partityla infecting pecan (Carya illinoinensis) wasused as a control. mtDNA region was amplified with the C2F3/1108 primer set and produced a fragment of approximately 530 bp, whereas the 8S rDNA amplified using primers 18Ss1.2 (5?-GGCGATCAGATACCGCCCTAGTT-3?) and 18SR2B(5?-TACAAAGGGCAGGGACGTAAT-3?) resulted in an amplicon of ca 630 bp, both ofwhich are identical to those previously reported for M. partityla. The rDNA ITS was amplified with ITS-1 F (CGCAGTGGCTTGAACCGG) and a primer shown only to anneal in M. partityla, MpSpec (TGAACTTTTATTGGTGAAAG) and sequenced. The amplificationsize using this species-specific primer combination for females found infecting both water oak (GenBank # KR047556) and pecan (GenBank # KR047555) was ca. 500 bp, which is in agreement with that found in M. partityla infecting pecan inArizona, Florida, Georgia, New Mexico, Oklahoma and Texas. Studies are in progress to determine whether M. partityla infecting oaks can also infect pecan and vice versa, and further elucidate the phylogenetic relationship among thesenematode populations.