Soybean (Glycine max L.) is one of the most economically important crops in Brazil and in the world. Among soil-borne plant pathogens that affect soybean, the root-knot nematodes (Meloidogyne spp.) cause serious damage to this crop in different growing regions of Brazil (Hartman et al. 2015). In Brazil M. javanica, M. incognita, M. arenaria, M. morocciensis, M. paranaensis, M. ethiopica and M. enterolobii are reported in soybean (Castro et al. 2003; Almeida et al. 2008), but M. luci has not been detected before. In November 2015, soybean plants (cv. Nidera 5909) exhibiting many galls on the roots were detected and sampled in areas from Palmeira das Missões (-27°49'41"S; -53°20'06"W) county, northwest Rio Grande do Sul State, Brazil. The identification of Meloidogyne was carried out by esterase phenotypes (n=30) (Carneiro and Almeida 2001), perineal patterns (n=20), morphological measurement of second-stage juveniles (J2) (n=20) and sequencing of the ribosomal DNA region D2-D3 of 28S (primer set: forward 5...

Considering the economic importance of strawberry in Brazil, with a clear migration trend from the soil to innovative systems on substrates, it is fundamental to evaluate the available cultivars in the market regarding tolerance to pathogens with potential for infestation. The reaction of eight commercial strawberry cultivars (Festival, Camino Real, Camarosa, Oso Grande, Monterey, San Andreas, Aromas, and Albion) to Meloidogyne and Pratylenchus species was evaluated. Strawberry cultivars were maintained in individual pots with sterilized soil and inoculated with 5,000 eggs + second stage juveniles of Meloidogyne arenaria, M. incognita, M. javanica or M. hapla or 1,000 specimens of Pratylenchus zea or P. brachyurus per plant. The experiment was carried out in a completely randomized design with six replications using tomato ‘Rutgers’ and sorghum ‘506’ plants as control to root-knot and lesion nematodes, respectively. Ninety days after inoculation, the nematode reproduction factor (RF= final population/initial population) was evaluated to determine the resistance of the strawberry genotypes to each nematode species. All cultivars behaved as resistant (FR1.00) to M. arenaria and M. hapla and ‘Oso Grande’ behaved as a good host to M. hapla; however, the other cultivars were resistant to these two Meloidogyne species. The assessed cultivars are poor hosts, being an alternative to be used in infested areas with these pests.

Early and non-destructive detection of plant-parasitic nematodes is critical for implementing site-specific management in coffee production systems. This study evaluated the potential of unmanned aerial vehicle (UAV) multispectral and thermal imaging, combined with textural analysis, to detect Meloidogyne exigua infestation in Coffea arabica (Topázio variety). Field surveys were conducted in two contrasting seasons (dry and rainy), and nematode incidence was identified and quantified by counting root galls. Vegetation indices (NDVI, GNDVI, NGRDI, NDRE, OSAVI), individual spectral bands, canopy temperature, and Haralick texture features were extracted from UAV-derived imagery and correlated with gall counts. Under the conditions of this experiment, strong correlations were observed between gall number and the red spectral band in both seasons (R > 0.60), while GNDVI (dry season) and NGRDI (rainy season) showed strong negative correlations with gall density. Thermal imaging revealed moderate positive correlations with infestation levels during the dry season, indicating potential for early stress detection when foliar symptoms were absent. Texture metrics from the red and green bands further improved detection capacity, particularly with a 3 × 3 pixel window at 135°. These results demonstrate that UAV-based multispectral and thermal imaging, enhanced by texture analysis, can provide reliable early indicators of nematode infestation in coffee.

However, intensive planting and expansion of croplands to new areas have intensified phytosanitary problems, particularly those related to plant parasitic nematodes. In this context, the species Meloidogyne javanica and M. incognita are widely distributed in the soybean growing areas of Brazil (^{DIAS et al., 2010}). Other species have been reported in different regions of the world, such as M. graminicola in China (^{LONG et al., 2017}). This must be taken into consideration when planting soybeans in areas previously destined for the rice sector. In addition, recently, there have been frequent reports of an atypical population, called Meloidogyne sp.0, in southern Brazil (^{MATTOS et al., 2017}). Therefore, the objective of this study was to evaluate the response of soybean genotypes to M. javanica, Meloidogyne sp.0, and M. graminicola, under greenhouse conditions.

Root-knot nematodes ( Meloidogyne spp.) threaten global agricultural production. Bacteria that inhabit the nematode egg mass have not been well explored. Using a metataxonomic approach based on sequencing the 16S rRNA gene of bacteria communities associated with Meloidogyne exigua egg masses, we found significant differences in bacterial composition and diversity in the egg masses of symptomatic coffee plants compared with asymptomatic ones for the first time in field conditions. The families Pseudomonadaceae, Burkholderiaceae, Flavobacteriaceae, Rhizobiaceae, Micrococcaceae, and Bacteroidaceae were more abundant in egg masses sampled from asymptomatic plants, and Chitinophagaceae, Glycomycetaceae, Micropepsaceae, Beijerinckiaceae, and Enterococcaceae were more abundant in samples from symptomatic plants. The genera Pseudomonas, Sphingobacterium, Flavobacterium, Corynebacterium, and Virgibacillus were found in greater abundance in egg masses from asymptomatic plants, and only Tumebacillus and Bacillus were significantly more abundant in samples from symptomatic plants. The reproduction and infectivity of M. exigua was tested in tomato plants. The reproduction index of M. exigua (nematodes eggs per gram of roots) was significantly lower when applying nematode inocula from asymptomatic coffee plants compared with inocula from symptomatic plants. The root weight of tomato plants infected with inocula from asymptomatic coffee plants was significantly higher than that of plants infected with inocula from symptomatic plants. However, there was no significant difference in the infectivity index (number of galls per root system) of tomato plants when inoculated with inocula from either source ( P ≤ 0.05). This study showed a differential bacterial community colonizing coffee plants with different levels of nematode infections, which opens the door for future nematode biological control. [ ] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Plant-parasitic nematodes Meloidogyne incognita and Pratylenchus zeae are commonly associated to sugarcane in Brazil causing serious problems. Thus, the objectives of this study were to determine the reproductive rate of M. incognita and M. enterolobii in sugarcane when inoculated in isolation and together with P. zeae and the effects of this interaction on the early development of two varieties of sugarcane. Two experiments were performed. In the first experiment, three different population densities of M. incognita and M. enterolobii were inoculated in both sugarcane varieties. In the second experiment, inoculation of P. zeae followed by inoculation with M. incognita or M. enterolobii was carried out. Meloidogyne enterolobii did not show good development in both sugarcane varieties after 120 days of infestation; contrary to M. incognita, which reached high population levels. Fresh and dry shoot biomasses were lower under joint infestation of P. zeae and Meloidogyne. In mixed infections, P. zeae suppressed the development of M. incognita and increased the multiplication of M. enterolobii in the variety RB867515 whereas the contrary was observed in the variety RB92579, demonstrating once more the resistance reaction of this variety to M. enterolobii.