Unveiling the structure and distribution of plant-parasitic nematode communities in soybean fields in southern of the Brazil

Our study aimed to assess the structure and distribution of plant-parasitic nematodes in soybean [Glycine max (L.) Merr] in the south of Brazil. High taxonomical diversity was found, with records of 10 genera of plant-parasitic nematodes (PPNs), including important pests, such as Meloidogyne (mostly M. javanica with small esterase variability), Pratylenchus (mostly P. brachyurus) and Helicotylenchus spp. The Shannon-Weaver index (H-') ranged from 0 to 1.23 (mean = 0.37), whereas Pielou's evenness (J) ranged from 0 to 1 (mean = 0.51). The amount of PPNs (0 to 22,050 per 250 cm(3) soil, and 0 to 15,500 per 10 g roots), incidence and abundance for Meloidogyne (28.6%; 50 to 19,250 per 250 cm(3)), Pratylenchus (45.1%; 50 to 550 per 250 cm(3)), Helicotylenchus (91.2%; 50 to 9,150 per 250 cm(3)), Tylenchus (34.1%; 50 to 550 per 250 cm(3)), Xiphinema (33%; 50 to 250 per 250 cm(3)), Mesocriconema (15.4%; 50 to 2,000 per 250 cm(3)), Rotylenchus (8.8%; 50 to 1,900 per 250 cm(3)), Hemicycliophora (1.1%; 50 per 250 cm(3)), Discocriconemella (1.1%; 950 per 250 cm(3)) and Tylenchorhynchus (1.1%; 50 per 250 cm(3)) were related differently to the bioclimatic variables under analysis. Our findings provide an update for the status of PPNs in the south of Brazil and suggest important epidemiological issues linked to the management of these pests in the near future.

Automated summary

This study evaluated the structure and distribution of plant-parasitic nematodes in soybean fields in the south of Brazil, revealing high taxonomical diversity with 10 genera identified. Different plant-parasitic nematodes showed varying associations with bioclimatic variables, suggesting complex relationships between pest abundance and environmental conditions.