Incidence de quelques facteurs agronomiques sur les populations de Meloidogyne spp. et leurs principaux organismes parasites en culture maraîchère sahélienne

Nematology ◽  
2000 ◽  
Vol 2 (8) ◽  
pp. 895-906 ◽  
Author(s):  
Thierry Mateille ◽  
Bouma Thio ◽  
Yanougo Konate ◽  
Abdoussalam Sawadogo ◽  
Mamadou Diop
Keyword(s):  
Burkina Faso ◽  
Correspondence Analysis ◽  
Cultural Practices ◽  
Cropping Systems ◽  
Natural Occurrence ◽  
Pasteuria Penetrans ◽  
Population Densities ◽  
Contrôle Biologique ◽  
Lutte Culturale ◽  
Meloidogyne Spp

AbstractDes prospections nématologiques ont été réalisées dans les régions de production maraîchère de deux pays sahéliens, le Burkina Faso et le Sénégal. Des analyses de correspondances entre quelques facteurs agronomiques et les populations de Meloidogyne spp. ont montré que les niveaux des populations telluriques et racinaires n'étaient pas exclusivement liées à la sensibilité des cultures maraîchères en place, mais dépendaient aussi des précédents culturaux ou des agrosystèmes (terres inondées ou exondées) qui prévalent dans ces régions. En outre, la présence de micro-organismes parasites des nématodes (champignons nématophages et Pasteuria penetrans) dans les agrosystèmes de terres exondées, permet d'envisager l'intégration de méthodes de contrôle biologique à l'aide d'hyperparasites indigènes aux méthodes de lutte culturale. Impact of agronomic factors on Meloidogyne spp. populations and their most common parasites in Sahelian vegetable cropping systems - Nematode surveys were carried out in vegetable producing areas in two Sahelian countries, Burkina Faso and Senegal. Correspondence analysis between agronomical factors and populations of Meloidogyne spp. revealed that vegetable susceptibility to nematodes was not the only factor responsible for soil and root infestations. Population densities would more readily depend on cropping systems (previous crops, often flooded lowlands vs well drained uplands). Natural occurrence of nematode-parasitic microorganisms (nematophagous fungi and Pasteuria penetrans) in upland agrosystems was observed and could be used together with cultural practices in an IPM approach.

Cultural Openness as an Emerging Form of Cultural Capital in Contemporary France

2017 ◽  
Vol 11 (2) ◽  
pp. 145-164 ◽  
Author(s):  
Philippe Coulangeon
Keyword(s):  
Cultural Capital ◽  
20Th Century ◽  
Correspondence Analysis ◽  
Mass Culture ◽  
Cultural Practices ◽  
Global Culture ◽  
Capital Endowment ◽  
Educational Structures ◽  
Cultural Openness

This article explores the changing pattern of cultural privilege in contemporary France. Using French data on cultural practices, including variables on ‘highbrow’ culture, mass culture and cosmopolitan culture, we apply a multi-correspondence analysis (MCA). The findings first show that cultural privilege among French social and educational elites remains primarily a matter of cultural capital endowment, with a structuring contrast between ‘legitimate’ and ‘mass’ culture. The MCA also shows an additional divide between local and global culture underpinned by a strong age gradient. Yet the emergence of a changing pattern of cultural privilege among the youngest cohorts does not imply any clear reduction in cultural inequalities. Rather, it suggests a growing cultural distinctiveness of French elites. Finally, these tendencies should not be easily extrapolated to other contexts as they reflect strong French specificities related to the evolution of social and educational structures during the second half of the 20th century.

scholarly journals Cropping System Effects on Soil Monosaccharides in Western Burkina Faso

2017 ◽  
Vol 5 (4) ◽  
pp. 97
Author(s):  
Badiori Ouattara ◽  
Idriss Sermé ◽  
Korodjouma Ouattara ◽  
Michel P Sédogo ◽  
Hassan Bismark Nacro
Keyword(s):  
Burkina Faso ◽  
Microbial Activity ◽  
Soil Depth ◽  
Cropping Systems ◽  
Soil Aggregates ◽  
Sugar Content ◽  
Cropping System ◽  
Total Sugar Content ◽  
Fallow Lands ◽  
Western Burkina Faso

Labile pools of soil organic matter (SOM), including soil sugars, are important to the formation and stabilization of soil aggregates and to microbial activity and nutrient cycling. The effects of cropping systems at farm level in tropical areas on SOM labile pool dynamics have not been adequately studied and the results are sparse and inconsistent. The objective of this study was to determine the effects of soil management intensity on soil sugar monomers derived from plant debris or microbial activity in cotton (Gossypium herbaceum)-based cropping systems of western Burkina Faso. Thirty-three (33) plots were sampled at 0-15 cm soil depth considering field-fallow successions and tillage intensity. Two pentose (arabinose, xylose) and four hexose (glucose, galactose, mannose, glucosamine) monomers accounted for 2 to 18% of soil organic carbon (SOC) content. Total sugar content was significantly less with tillage, especially for the hexose monomeric sugars glucose and mannose, the latter of microbial origin. Soil mannose was 63 and 80% less after 10 years of cultivation, without and with annual ploughing respectively, compared with fallow conditions. Soil monosaccharide content was rapidly restored with fallow and soon approached the equilibrium level observed under old fallow lands. Therefore, the soil monosaccharides, in particular galactose and mannose from microbial synthesis are early indicators of changes in SOC.

Development of Pasteuria penetrans on different field populations of Meloidogyne spp. from Pakistan

Nematology ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1003-1010
Author(s):  
Muhammad Kamran ◽  
Nazir Javed ◽  
Huma Abbas ◽  
Sajid Aleem Khan ◽  
Ihsan Ullah ◽  
...  
Keyword(s):  
Biological Control ◽  
Root System ◽  
Biological Control Agent ◽  
Control Agent ◽  
Pasteuria Penetrans ◽  
Successful Development ◽  
Nematode Reproduction ◽  
Tomato Roots ◽  
Differential Infectivity ◽  
Meloidogyne Spp

Summary Pasteuria penetrans is a hyperparasite with potential as a biological control agent of root-knot nematodes, Meloidogyne spp. In this study two exotic Pasteuria isolates (PP-3 and PP-J) were developed on different Meloidogyne spp. collected from different districts of Punjab, Pakistan. The development of PP-3 and PP-J on different field populations of Meloidogyne spp. showed differential infectivity in terms of nematode reproduction variables. The development of PP-3 and PP-J was maximum on tomato as compared to cucumber. It was probably due to more invasion sites for nematodes present in the tomato roots. However, a bigger root system has not always been a guarantee for development of Pasteuria on Meloidogyne spp. For successful development of Pasteuria, the key parameters are the percentage of infected females, number of endospores (female)−1 or endospores (mg root powder)−1. The results of these parameters are greater in tomato as compared to cucumber.

Soil abiotic factors associated with Meloidogyne spp. and Pratylenchus spp. populations in sugarcane

Nematology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Marissônia de A. Noronha ◽  
Marcelo F. Fernandes ◽  
Maria de Fatima S. Muniz ◽  
Elvira Maria R. Pedrosa ◽  
Mayara C. Assunção ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Zone ◽  
Abiotic Factors ◽  
Regression Tree ◽  
Parasitic Nematodes ◽  
Population Densities ◽  
Multivariate Regression Tree ◽  
Soil Variables ◽  
Meloidogyne Spp

Summary Meloidogyne spp. and Pratylenchus spp. are the most damaging plant-parasitic nematodes to sugarcane and the knowledge of soil characteristics that influence the occurrence of these pathogens can be useful in their management. With the objective to investigate the relationships between soil variables and populations of Meloidogyne spp. and Pratylenchus spp. in sugarcane fields, root-zone soil and root samples were collected from 20 farms located in 16 municipalities in Alagoas state, Brazil. The multivariate regression tree technique was used to model the population density’s response variables for Meloidogyne spp. and Pratylenchus spp. in the root-zone soil and the roots according to sugarcane cultivars, soil organic matter, and soil chemical and physical variables. The results showed the existence of associations between soil factors, sugarcane cultivars and populations of nematodes. Root samples from soils with K > 37.79 mmolc dm−3, Al < 5.93 mmolc dm−3 and sugarcane ‘RB92579’, ‘SP753046’, ‘SP813250’ and ‘SP921631’ showed the lowest Pratylenchus spp. population densities. However, the lowest densities in the root-zone were found in soils with sum of bases > 1.91 mmolc dm−3, Ca:Mg ratio < 1:2 and soil organic matter < 10.7 g dm−3. The lowest population densities of Meloidogyne spp. in roots were associated with sugarcane ‘RB92579’, ‘RB93509’, ‘RB98710’, ‘SP791011’ and ‘SP921631’ and soil aggregate mean diam. > 0.48 mm, while root-zone densities were minimum in soils with P > 28.59 mg dm−3. This information should support further studies to investigate the effect of each variable on populations of Pratylenchus and Meloidogyne.

Attachment of endospores of Pasteuria penetrans to males and juveniles of Meloidogyne spp.

Nematology ◽  
1999 ◽  
Vol 1 (3) ◽  
pp. 267-271 ◽  
Author(s):  
Regina M.D.G. Carneiro ◽  
Onivaldo Randig ◽  
Leandro G. Freitas ◽  
Don W. Dickson
Keyword(s):  
Rio Grande ◽  
In Vitro Assays ◽  
Similar Degree ◽  
Pasteuria Penetrans ◽  
Race 1 ◽  
Meloidogyne Spp ◽  
Race 2 ◽  
Pratylenchus Scribneri ◽  
Meloidogyne Sp

Abstract The attachment of endospores to Meloidogyne spp. males and second stage juveniles (J2) was evaluated in two different in vitro assays of seven isolates of Pasteuria penetrans from Florida, USA. In the first assay, endospores of all seven isolates adhered to J2 but not males of M. arenaria race 1. In the second assay, two isolates differed in the specificity of spore attachment to J2 of six Meloidogyne spp. Isolate B4, from Pratylenchus scribneri, showed a similar degree of attachment to J2 of M. arenaria race 2, M. javanica (two populations) and to M. incognita race 3, but did not attach to males of seven species. Isolate P100, from Meloidogyne sp., had high rates of attachment to M. javanica from Rio Grande do Sul State and to M. paranaensis, but lower rates to M. arenaria and M. javanica from Parana State. These data indicate that attachment ability depends not only on the Meloidogyne species but also on the particular population of a species. The high rate of attachment to male but not J2 M. hapla indicates that endospore attachment may also depend upon nematode stage, species, race and population and on Pasteuria isolate. Germinated endospores attached to male M. hapla were examined by scanning electron microscopy but few had successfully penetrated the cuticle. Adhesion des endospores de Pasteuria penetrans aux males et juveniles de Meloidogyne spp. - L'adhesion des spores de Pasteuria penetrans aux males et juveniles de deuxieme stade (J2) de Meloidogyne spp. a ete evaluee lors de deux differents tests in vitro comprenant sept isolats de P. penetrans provenant de Floride, USA. Lors du premier test les endospores des sept isolats ont adhere aux J2 mais non aux males de M. arenaria race 1. Lors du second test deux isolats se sont distingues quant a la specificite de l'adhesion de leurs spores aux J2 de six des especes de Meloidogyne. L'isolat B4, provenant de Pratylenchus scribneri, montre un taux d'adhesion similaire vis-a-vis des J2 de M. arenaria race 2, M. javanica (deux populations) et M. incognita race 3, mais n'adhere aux males d'aucune des sept especes. L'isolat P 100, provenant de Meloidogyne sp., Montre un taux d'adhesion eleve vis-a-vis tant de M. javanica provenant de l'Etat de Rio Grande del Sul que de M. paranensis mais ce taux est faible vis-a-vis de M. arenaria et M. javanica originaires de l'Etat du Parana. Ces donnees indiquent que la faculte d'adhesion depend non seulement de l'espece de Meloidogyne en cause mais egalement de la population particuliere de cette espece. Le taux eleve d'adhesion vis-a-vis des males, mais non des J2, de M. hapla indique que cette adhesion peut dependre du stade de developpement du nematode, de son espece, race ou population ainsi que de l'isolat lui-meme de P. penetrans. Les endospores fixees aux males de M. hapla, et ayant germe, ont ete examinees en microscopie electronique a balayage: peu d'entre elles avaient reussi a traverser la cuticule.

Effects of nematode infection and mulching on the yield of plantain (Musa spp., AAB-group) ratoon crops and plantation longevity in southeastern Nigeria

Nematology ◽  
2005 ◽  
Vol 7 (4) ◽  
pp. 531-541 ◽  
Author(s):  
Annemarie Auwerkerken ◽  
Thomas Dubois ◽  
Bart De Schutter ◽  
Paul Speijer ◽  
Omalara Rotimi ◽  
...  
Keyword(s):  
Nematode Infection ◽  
International Institute ◽  
Radopholus Similis ◽  
Population Densities ◽  
Southeastern Nigeria ◽  
Musa Spp ◽  
Root Necrosis ◽  
Meloidogyne Spp ◽  
Crop Cycle ◽  
Plant Crop

AbstractThe effects of nematode infection and mulching on plantain cv. Agbagba (Musa spp., AAB-group, false horn) yield and plantation longevity were examined in a field experiment at the High Rainfall Station of the International Institute of Tropical Agriculture (IITA) at Onne in southeastern Nigeria. The 2nd, 3rd and 4th crop cycles (1st, 2nd and 3rd ratoon, respectively) following the plant crop cycle (mother crop) were examined in nematode inoculated or non-inoculated and mulched or non-mulched treatments. Nematodes (Radopholus similis, Helicotylenchus multicinctus and, to a lesser extent, Helicotylenchus dihystera, Hoplolaimus pararobustus and Meloidogyne spp.) were inoculated at planting of the mother plant, but were also present in relatively high population densities in the non-inoculated treatments at harvest of the 1st crop cycle. Plants inoculated with nematodes failed to reach harvest and neither did plants in the non-inoculated non-mulched treatments in any ratoon. Only non-inoculated mulched plants reached harvest, producing 0.85, 1.22 and 0.2 Mg ha−1, respectively in the 1st, 2nd and 3rd ratoon, taking toppled, broken and dead plants into consideration. Mulched plants were larger, had more suckers, survived longer and had healthier root systems compared with non-mulched plants. Damage to roots was greater in the inoculated plants compared with the non-inoculated plants for the 1st and 2nd ratoons but not for the 3rd ratoon. Radopholus similis was most strongly associated with root damage (percentage root necrosis and dead roots), although H. multicinctus population densities were also positively correlated with percentage root necrosis. At flowering of the 1st ratoon, 71% of the inoculated non-mulched plants were dead compared with only 1% of the non-inoculated mulched plants. Helicotylenchus multicinctus remained the most abundant nematode throughout the experiment. Together with R. similis, it comprised over 95% of the plant-parasitic nematode population.

The 16S rRNA gene of Pasteuria penetrans provides an early diagnostic of infection of root-knot nematodes (Meloidogyne spp.)

Nematology ◽  
2012 ◽  
Vol 14 (7) ◽  
pp. 799-804 ◽  
Author(s):  
Uma Rao ◽  
Tim H. Mauchline ◽  
Keith G. Davies
Keyword(s):  
Innate Immunity ◽  
Meloidogyne Incognita ◽  
Rrna Gene ◽  
Pasteuria Penetrans ◽  
Root Knot Nematodes ◽  
Flexible Approach ◽  
Obligate Parasites ◽  
Meloidogyne Spp ◽  
The 16S Rrna Gene ◽  
Early Diagnostic

The molecular interactions between hosts and parasites is an active area of research, and the parasitism of root-knot nematodes, obligate parasites of plants, by the hyper-parasitic bacterium Pasteuria penetrans offers a model by which to investigate aspects of innate immunity. Using a pouch system we were able to demonstrate by PCR, infection of Meloidogyne incognita 4 days prior to any microscopic observations of parasitism. The pouch system, although not strictly axenic, offered a relatively clean, flexible approach with a greatly reduced number of contaminating microbial species than in any soil-based system, whereby the early stages of nematode infection could be manipulated and controlled.

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