Fig 1.
Geographic locations of all sample sites (upper map) and sample sites where root-knot nematodes of the genus Meloidogyne were found (lower map).
This map may be similar but not identical to other published maps of Andalusia and is used only for the purpose of showing the sampling sites.
Table 1.
Taxa sampled for Meloidogyne species and sequences used in this study.
Table 2.
Explanatory variables sets used to assess community composition of Meloidogyne spp. in cultivated olives in Andalusia, southern Spain.
Table 3.
Soil nematode population density (number of specimens) per 500 cm3 of soil and prevalence (%) of Meloidogyne spp. in soil in wild and cultivated olives in Andalusia, southern Spain.
Table 4.
Nematode population density (number of specimens) and prevalence (%) of Meloidogyne spp. in roots of wild and cultivated olives in Andalusia, southern Spain.
Fig 2.
Line drawings of Meloidogyne oleae sp. nov., female, male and second-stage juvenile paratypes.
A) Entire body of female. B) Anterior region of female. C, D) Perineal pattern. E) Anterior region of male. F) En face view of male lip region. G) Male tail. H) Pharyngeal region of second-stage juvenile. I) En face view of second-stage juvenile lip region. J-M) Second-stage juvenile tails. Scale bars: A = 200 μm; B-E, G, H = 20 μm; F = 5 μm; I = 2 μm; J-M = 10 μm.
Fig 3.
Light micrographs of Meloidogyne oleae sp. nov., female paratypes.
A) Whole female. B–E) Detail of female perineal patterns. Scale bars: A = 100 μm; B-E = 20 μm.
Fig 4.
Light micrographs of Meloidogyne oleae sp. nov., male and second-stage juvenile paratypes.
A) Whole male. B-D) Male lip region. E-F) Male tail showing spicules. G) Detail of sperm cells. H) Detail of embryonated egg showing stylet of second-stage juvenile. I) All life stages. J) Whole second-stage juvenile. K) Anterior region of second-stage juvenile showing excretory pore, stylet and dorsal gland orifice. L–Q) Tail of second-stage juveniles (J2). Abbreviations: a = anus; dgo = dorsal gland orifice; = ep = excretory pore; sp = spicules; st = stylet. Scale bars: A, I = 100 μm; B-H, J-Q = 10 μm.
Fig 5.
SEM micrographs of Meloidogyne oleae sp. nov., female paratypes.
A, B) Female lip region showing position of excretory pore and amphidial aperture. C) Whole female included in wild olive root. D) Detail of female perineal pattern. Abbreviations: aa = amphidial aperture; ep = excretory pore; st = stylet; V = vulva. Scale bars A, B = 2 μm; C = 500 μm; D = 10 μm.
Fig 6.
SEM micrographs of Meloidogyne oleae sp. nov., male paratypes.
A) Anterior region showing smooth lip region, amphidial aperture, and endospore bacterial of Pasteuria sp. B) En face view showing amphidial and oral apertures. C, D) Detail of tail showing lateral field and spicules. Abbreviations: aa = amphidial aperture; oa = oral aperture; lf = lateral field; Ps = endospore Pasteuria sp.; slr = smooth lip region. Scale bars A, C, D = 5 μm; B = 1 μm.
Fig 7.
SEM micrographs of Meloidogyne oleae sp. nov., second-stage juvenile paratypes.
A, B) Smooth lip region and amphidial aperture. C) En face view of lip region showing amphidial and oral apertures. D) Detail of lateral field at mid-body. E-F) Tail. Abbreviations: a = anus; aa = amphidial aperture; oa = oral aperture; lf = lateral field; slr = smooth lip region. Scale bars A, D-F = 2 μm; B, C = 1 μm.
Fig 8.
Esterase (Est) (in black) and malate dehydrogenase (Mdh) (in purple) electrophoresis patterns of protein homogenates from five young, egg-laying females of Meloidogyne oleae n. sp. nov., and five young, egg-laying females of M. javanica (reference population).
Fig 9.
Histological sections of Meloidogyne oleae sp. nov. on wild (A-F) and cultivated (G-I) olives. A, D, G. Transverse section of young olive roots showing permanent feeding sites in vascular parenchyma. I. Apical longitudinal section showing initial infections by second-stage juveniles or J2 (arrow). B, C, E, F, H. Detailed images of feeding sites showing multinucleate giant cells with hypertrophied nuclei and nucleoli. Staining: toluidine blue O. Abbreviations: fs = feeding site; gc = giant cell; hn = hypertrophied nuclei; J2 = second-stage juvenile; n = nuclei. Scale bars = A, B, D, E, G, I = 100 μm; C, F, H = 10 μm.
Fig 10.
Histological sections of Meloidogyne oleae sp. nov. on lesser periwinkle (Vinca minor L.) (A-E) and rosebush (Rosa sp.) (F-J). A, F. Transverse sections of healthy lesser periwinkle and rosebush roots. B, C. G. Transverse sections of young lesser periwinkle and rosebush roots showing permanent feeding sites in vascular parenchyma. D, E, H, I, J. Detailed images of feeding sites showing multinucleate giant cells with hypertrophied nuclei and nucleoli. Staining: toluidine blue O. Abbreviations: fs = feeding site; gc = giant cell; hn = hypertrophied nuclei; n = nuclei. Scale bars = 100 μm.
Table 5.
Morphometrics of females, males and second-stage juveniles of Meloidogyne oleae sp. nov. from the rhizosphere of wild olive at Tolox (Málaga province) southern Spaina.
Table 6.
Morphometrics of males and second-stage juveniles of Meloidogyne oleae sp. nov. from the rhizosphere of cultivated olive at Antequera (Málaga province) southern Spaina in sampling point JAO28 and JAO31.
Fig 11.
The 50% majority rule consensus tree from Bayesian inference analysis generated from the D2-D3 of 28S rRNA gene dataset of Meloidogyne spp. with the TIM3+I+G model.
Posterior probabilities more than 0.70 are given for appropriate clades. Newly obtained sequences are in bold letters. Scale bar = expected changes per site.
Fig 12.
The 50% majority rule consensus trees from Bayesian inference analysis generated from the ITS rRNA gene dataset of Meloidogyne spp. with the TIM2+I+G model.
Posterior probabilities more than 0.70 are given for appropriate clades. Newly obtained sequences are in bold letters. Scale bar = expected changes per site.
Fig 13.
The 50% majority rule consensus trees from Bayesian inference analysis generated from the partial 18S rRNA gene dataset of Meloidogyne spp. with the GTR+I+G model.
Posterior probabilities more than 0.70 are given for appropriate clades. Newly obtained sequences are in bold letters. Scale bar = expected changes per site.
Fig 14.
The 50% majority rule consensus trees from Bayesian inference analysis generated from the partial coxII-16S mtDNA gene dataset of Meloidogyne spp. with the TVM+I+G model.
Posterior probabilities more than 0.70 are given for appropriate clades. Newly obtained sequences are in bold letters. Scale bar = expected changes per site.
Fig 15.
The 50% majority rule consensus trees from Bayesian inference analysis generated from the partial coxI gene dataset of Meloidogyne spp. with the GTR+G model.
Posterior probabilities more than 0.70 are given for appropriate clades. Newly obtained sequences are in bold letters. Scale bar = expected changes per site.
Table 7.
Forward selection procedure results of ecological predictors in explaining community patterns of root-knot nematodes (RKNs) infesting soils of olive orchards from cultivated olive in Andalusia (southern Spain).
Fig 16.
Canonical ordination analyses of Hellinger-transformed prevalence Meloidogyne spp. data on cultivated olives with respect to environmental variables.
The response variables are the fitted explanatory variables from the four data set (i.e. climate, soil, topography and agronomic management) by forward selection procedure. A) Ordination plots of the redundancy analyses used to investigate the relationships between prevalence of Meloidogyne spp. and explanatory variables. Ecological predictors are represented on the plots as agronomic practices related with irrigation regimen (Irrigation) and cover vegetation on alley (Cover on alley), and soil loamy sand texture (Loamy sand texture) on olive orchards. The first canonical axis (RDA axis 1) explains 85.9% of species-variables relationships, and the second axis (RDA axis 2) explains 11.2%. B) Trend-surface analysis of the canonical axis 1 of the RDA analysis. Spatial structure variation related with agronomic practices including Irrigation (P<0.001) and Cover on alley (P<0.001) variables. C) Trend-surface analysis of the canonical axis 2 of the RDA analysis. Spatial structure variation related with soil properties including soil loamy sand texture (P<0.05). For trend-surface analyses, fitted sampling site scores from RDA are plotted on geographical coordinates. Sampling sites with the same colours show similarly trends of relationships between Hellinger-transformed prevalence of Meloidogyne spp. data and explanatory variables of cultivated olives; symbol size indicates the level of similarly (i.e. small symbols for low similarity, and large symbols for high similarity. Interpretation of the spatial variation with respect to explanatory variables was performed using regression analyses of the two canonical axes on the environmental variables after normality tests.