First Report of Meloidogyne javanica Parasitizing Duboisia sp. in Paraná State, Brazil.

Duboisia sp. is a small tree belonging to the family Solanaceae originating from the rainforest areas of the eastern coast of Australia. Dried leaves are used for the extraction of pharmaceutical alkaloids, making this a commercially viable crop. The root-knot nematode Meloidogyne incognita has been reported parasitizing Duboisia myoporoides (5); however, no information of other root-knot nematode species associated with this plant was found. Duboisia sp. is cultivated at Solana Farm, near Arapongas (23°25'08″ S, 51°25'26″ W), Paraná State, Brazil. During the renovation of a production field in this municipality, galled roots were observed on plants and samples were submitted to the Nematology Laboratory at Instituto Agronômico do Paraná, IAPAR, on December 2013. Plants did not exhibit any above-ground symptoms. The specimens were identified through perineal patterns and esterase phenotypes of 20 adult females extracted from dissected roots (2,3) and morphometrics of 10 second-stage juveniles extracted from roots using the blender-sieving method (1). Morphological characteristics were consistent with those described for M. javanica (4). Females had rounded perineal patterns with low, trapezoid shape dorsal arch, striae smooth interrupted by a pair of incisures on both sides, corresponding to lateral fields, clearly demarcated from striae by more or less parallel lines, tail whorl often distinct (4). The juvenile mean body length was 459.9 ± 28.7 µm and tail length averaged 51.6 ± 5.1 µm, with 10 to 16 µm long hyaline region and finely rounded tail tip (4). Results from the esterase electrophoresis were typical of M. javanica (2) with the J3 (Rm = 1.0, 1.3, and 1.4) phenotype being obtained. To our knowledge, this is the first report of M. javanica on Duboisia sp. in Brazil. This finding has great importance for Brazilian production since this nematode may damage plants, reduce yields, and control of this nematode on Duboisia sp. is difficult (5). Additional work is necessary in order to elucidate the losses caused by M. javanica on Duboisia sp. References: (1) J. I. Bonetti and S. Ferraz. Fitopatol. Bras. 6:533, 1981. (2) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 22:10, 1990. (3) K. M. Hartman and J. N. Sasser. Page 115 in: An Advanced Treatise on Meloidogyne. Volume II Methodology. K. R. Barker et al., eds. North Carolina State University Graphics, Raleigh, 1985. (4) D. J. Hunt and Z. A. Handoo. Page 55 in: Root-Knot Nematodes. R. N. Perry et al., eds. CABI International, Wallingford, UK, 2010. (5) A. M. Mello et al. Nematol. Bras. 22(2):12, 1998.

First Report of the Root Knot Nematode, Meloidogyne inornata, on Common Bean in Paraná State, Brazil.

Common bean (Phaseolus vulgaris F.) is one of the most important crops in Paraná State, which is responsible for almost 10% of the Brazilian production (4). Root knot nematodes, Meloidogyne spp., are common parasites of this crop worldwide, but damage caused by Meloidogyne inornata has not been reported. During a survey of nematode species present on common bean fields in Paraná State, Brazil, galled root samples of cultivars Tuiuiú and Eldorado were submitted, in June 2012, in the Nematology Laboratory from IAPAR, collected in the municipalities of Araucária (25°35'34″S, 49°24'36″W) and Santana do Itararé (23°45'18″S, 49°37'44″W). Plants did not exhibit any above-ground symptoms. The specimens were identified through perineal patterns and esterase phenotypes of 20 adult females extracted from dissected roots (2,3). The population densities observed in the samples were 140 and 700 J2 and eggs per gram of roots, respectively, for both samples. Characteristics were consistent with those described for M. inornata. For example, perineal patterns of M. inornata showed a high dorsal arch, with smooth to wavy striae, similar to those of M. incognita; but no punctate markings between anus and tail terminus were observed. However, from the esterase electrophoresis we obtained the I3 (Rm = 0.83, 1.15, and 1.32) phenotype, typical of M. inornata, a species-specific phenotype used to differentiate this species from M. incognita (1). Moreover, the excretory pore of adult females was located 32.1 (± 5.4) µm from the anterior end, consistent with the M. inornata description (25 to 53 µm) (1). To the best of our knowledge, this is the first report of M. inornata parasitizing common bean roots. This finding has great importance for Brazilian agriculture, since this nematode may damage common bean plants and become an additional problem for this crop. Additional work is necessary in order to elucidate the losses caused by M. inornata on common bean. References: (1) R. M. D. G. Carneiro et al. Nematology 10:123, 2008. (2) P. R. Esbenshade and A. C. Triantaphyllou J. Nematol. 22:10, 1990. (3) K. M. Hartman and J. N. Sasser. Page 115 in: An Advanced Treatise on Meloidogyne, Volume II Methodology. K. R. Barker et al., eds. Raleigh: North Carolina State University Graphics, 1985. (4) MAPA. Feijão, Ministério da Agricultura, Brasil. Retrieved from http://www.agricultura.gov.br/vegetal/culturas/feijao September 05, 2012.