Methodological adaptation for nematodes extration in forest soils of the southern Mata Atlântica

Abstract

-The objective of this work was to clarify whether the method to extract nematodes from European soils is suitable for forest soils and litter in the eastern of Paraná state, Brazil, and whether nematode abundance differs between sites with different ecosystems and levels of human interference. The study sites were situated in the coastal area of the Serra do Mar, near the town of Antonina, in Eastern Paraná, Brazil. Cobb's sieving and decanting method was more appropriate than ISO method, since extraction effi ciency was higher and intrasample variability was signifi cantly lower. In order to achieve an extraction effi ciency higher than 90%, Cobb's method was modifi ed. For the extraction of nematodes from litter, the Baermann funnel, with an extraction time of 48 hours, yielded an extraction effi ciency higher than 90%. Nematode abundance in litter was higher than in soil. The mean number of individuals extracted from the litter increased with the age stage of the forest sites sampled, and there was no difference in the number of individuals in the soil of the four forest sites. Mean nematode abundance in soil in banana plantations was about twice as high compared to the banana-palmito mixed stands and to the forest sites.Index terms: agroforestry system, bioindicator, extraction method, Nematoda. Adaptação metodológica para extração de nematódeos em solos fl orestais da Mata Atlântica do Sul do BrasilResumo -O objetivo deste trabalho foi verifi car se o método de extração de nematódeos, aplicado em solos europeus, é apropriado para solos de fl orestas e para serapilheira do leste do Estado do Paraná, e se a abundância de nematódeos difere entre os diversos ecossistemas e os níveis de interferência humana. Os locais estudados situam-se na área costeira da Serra do Mar, próximo do Município de Antonina, no Leste do Paraná. O método Cobb de peneiramento e decantação foi considerado mais apropriado do que o método ISO, pois a efi ciência da extração foi maior, e a variabilidade intra-amostral foi signifi cativamente menor. Para conseguir uma efi ciência de extração acima de 90%, o método Cobb foi modifi cado. Para a extração de nematódeos da serapilheira, o funil de Baermann, com tempo de extração de 48 horas, rendeu efi ciência de extração acima de 90%. A abundância de nematódeos em serapilheira foi maior do que no solo. O número médio de indivíduos extraídos da serapilheira aumentou com a idade da fl oresta na área amostrada, e não houve diferença quanto ao número de indivíduos nos solos dos quatro sítios de fl oresta. A abundância média no solo dos plantios de banana foi quase o dobro da observada em sítios de plantio misto de banana com palmito e em sítios de fl oresta.Termos para indexação: sistema agrofl orestal, indicador biológico, método de extração, Nematoda.

A Comparative Study of Three Widespread Methods for Extracting Plant-Parasitic Nematodes from Soil Samples

“…Sarah and Boisseau (2008) referred that centrifugal flotation method can extract all nematode species and all life stages from the root and soil particles. Moser and Frankenbach (2009) found that the Cobb's method was more efficient than ISO method (International Organization for Standardization, 2005) in extraction nematodes from the soil samples and it achieved about 90% higher than the other methods of extraction. Mahesh Kumar et al (2012) indicated that the centrifugal method was the most efficient method for extracting all stages of plant-parasitic nematodes from the soil and plant materials when compared with other methods, and among of the genera extracted by this method were Meloidogyne, Pratylenchus, Rotylenchulus, and Tylenchorhynchus.…”

Year-Long Assessment of Soil Nematode Diversity and Root Inhibition-Indicator Nematode Genera in Rice Fields

“…Finally, 50 mL volume of soil suspension was used for nematode extraction. Nematodes were isolated sequentially using modified Cobb’s sieving and decantation (with mesh sieves of 833, 74, and 38 µm apertures) and Baermann’s funnel technique [ 34 ].…”