Impact of agricultural practices and environmental variables on plant-parasitic nematode communities in fields at a landscape scale

Nematology ◽  
2018 ◽  
Vol 20 (3) ◽  
pp. 211-233 ◽  
Author(s):  
Nathan Garcia ◽  
Laurent Folcher ◽  
Luc Biju-Duval ◽  
Agathe Maupetit ◽  
Benoit Ricci ◽  
...  

Agricultural practices shaping plant-parasitic nematode (PPN) assembly are still unclear, and this limits our understanding of the impact of anthropic disturbances on the resilience of PPN communities and the emergence of agronomic problems. Here the abundance and diversity of PPN in France’s oilseed rape production area was determined by sampling 72 fields over two consecutive years. We identified and counted PPN taxa and collected anthropic and environmental variables for the past 5 years. PPN were assigned to seven genera and one family including PPN that have not been identified to genus level. Using multiple correspondence analyses, we selected the main variables and tested their effect on the abundance of each taxon with mixed generalised linear models. We emphasise that at the landscape scale investigated, crop rotations were no longer a major factor impacting the PPN communities. However, we observed that tillage and pesticides had a significant impact on several taxa.

2016 ◽  
Vol 42 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Hannah W. Karuri ◽  
Daniel Olago ◽  
Roy Neilson ◽  
Editah Njeri ◽  
Alfred Opere ◽  
...  

Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.


2011 ◽  
Vol 47 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Perrine Tabarant ◽  
Cécile Villenave ◽  
Jean-Michel Risède ◽  
Jean Roger-Estrade ◽  
Marc Dorel

cftm ◽  
2017 ◽  
Vol 3 (1) ◽  
pp. cftm2016.12.0086 ◽  
Author(s):  
David L. Jordan ◽  
Tommy Corbett ◽  
Clyde Bogle ◽  
Barbara Shew ◽  
Rick Brandenburg ◽  
...  

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