Plant-parasitic nematode communities associated with olive in Morocco

Plant-parasitic nematode communities associated with olive

in Morocco : IRD

The 1st Interna,onal American Moroccan Agricultural Sciences Conference ‐ AMAS Conference 

March 18‐19, 2013 Rabat Morocco 

N. Ali1, E. Chapuis1, J. Tavoillot1, M. Aït Hamza2, A. El Mousadik2, A. El Oulkadi3, G. Besnard4, A. El Bakkali5, A. Moukhli3, B.

Khadari6, C. El Modafar7, M. Ater8, Z. Ferji9, T. Mateille1

1IRD, UMR CBGP, Mon;errier sur Lez, France; 2 UIZ‐FSA, Agadir, Morocco; 3 INRA, Marrakech, Morocco; 4 CNRS, UMR EDB, Toulouse, France; 5 INRA, Meknes, Morocco; 6 INRA, UMR AGAP, Montpellier, France; 7 UCAM‐FSTG, Marrakech, Morocco, 8 UAE‐FST, Tétouan, Morocco. 

9 IAV Hassan II, Agadir, Morocco 

  The Joint Research Unit: ecological approaches

  Introduction

  Plant-parasitic nematodes (PPN) communities … Why?   PPN: great pests in agriculture.   Objectives of the PhD study.   Olive (Olea europaea) as a host plant model for PPN communities.

 Materials and Methods

  Results about the survey done in olive soils in Morocco

  PPN diversity.   PPN community patterns.

  Conclusion

Table of contents

The Joint Research Unit … CBGP

  Several research and teaching institutions: INRA, IRD, CIRAD, SupAgro.

  Thematics: Systematics, Taxonomy, Phylogeny, Genetics, genomics and life history traits, Population genetics and Phylogeography, Ecology of populations and communities.

  Various biological models of interest (agriculture and human health): Arthropods, Nematodes, Rodents.

UMR CBGP Center for Biology and Management of Populations

  Research goals:   to elaborate conceptual and theoretic approaches and tools (molecular and

bioinformatic) in order to manage such organisms either through biological control or conservation strategies.

  to manage interacting communities which respond to global changes.

  PPN are everywhere present in communities (here

as species mixtures).

  Agricultural practices (cropping system, fertilization, weeding ...) affect diversity, trophic structure and composition of PPN communities.

  Crop production is not only affected by emblematic species but also depends on the structure of species communities.

Introduc,on  … Plant-parasitic nematode communities (PPN)… Why?

Pratylenchus

Meloidogyne Helicotylenchus Xiphinema

Paratrichodorus

F2

F1

high biomass low biomass

sugarcane growth

Lavelle et al., 2004

Research Program: Responses of PPN communities to anthropization and environmental constraints

Objectives: to characterize PPN community patterns in different ecosystems and to understand structure of communities

Introduction ... PPN: great pests in agriculture

Nematodes … What are they?   Round worms, unsegmented.   Successfully adapted to : - all altitudes - all regions (from polar to tropical regions). - every ecosystem (marine, fresh water and soils)   free-living or parasitic (humans, animals and plants).   27000 species described.

Soil Nematodes…   Very important biomass in the soil (100 - 1000 individuals /g soil).   Ecological importance: involved in different ecological processes:

carbon cycle, organic matter degradation, biological control agents, parasitism.   Various trophic groups: bacteriophagous, mycophagous, saprophagous,

predators of soil organisms and parasites of animals or plants (phytophagous).

Plant Parasitic Nematodes (PPN)…   PPN are nearly microscopic, living in soil or inside plants.   About 5000 species described.   Wide range of host plants.

Introduction ... PPN: great pests in agriculture

  Parasites difficult to control.

  Chemical control efficient and easy to use, but harmful impact on human health and environment.

  Legislations: restrictions and prohibitions.

  Need to develop other alternative methods.

IRD 

IRD 

Castillo et al., 2010

Dr. Weimin Ye 

  Significant economic damages: 20-30% of world crop production.

  Symptoms:   similar to environmental factors (sickly growth, wilting,

yellowing, stunting, …),   deformations   galls on roots for specific PPN species (Meloidogyne spp.)

Adaptation of PPN communities to olive cropping in the Mediterranean basin

Genetic variability of PPN population species (e.g. Meloidogyne spp.)

Diversity and community structure between different

olive cropping systems

Co-adaptation of PPN species to olive domestication

Intra- and interspecific interactions in communities

Impact of olive domestication and

cropping techniques on PPN communities 

Life traits of PPN population species

(e.g. Meloidogyne spp.)

Genetic variability of olive trees

Objectives of the PhD study... In few words

New strategies for PPN management

Introduction ... Olive (Olea europaea) as a host plant model for PPN communities

 Good example of plant diversity (relictual, wild, feral and cropped)   Different cropping systems (traditional and high density)

Evaluation of the PPN diversity between natural ecosystems (little or not affected by human activities) and agro-ecosystems (disturbed situations)

  Importance: cultural, economic and agronomic   Mediterranean Basin: 80% of the cultivated area 98% of the world production of olive oil.

  Different PPN species detected in olive : Meloidogyne spp., Pratylenchus spp., Helicotylenchus spp., …

  Significant yield losses in olive producing countries (Spain, Italy, Greece).   Higher incidence in nurseries.  Major problems following cropping intensification.

“Contribution of olive history for the management of soil-borne parasites in the Mediterranean basin” (EU-ARIMNet grant).

Tétouan

Chefchaouen

Meknès Séfrou

Imouzzèr

Beni Mellal Marrakech Asni

Taroudant

Rabat

Agadir Relictual (O. maroccana)

Wild Feral

Traditional Modern H.D

Materials and Methods …

  Different forms of olive trees: relictual, wild, feral and cropped    Sampling in Morocco in March and April 2012 (about 80 sites)

  Soil sampling: in cropped systems: 1 sample per plot (composite of 4 trees per plot) ⇒  5 plots per site. ⇒  5 replicates per site. in wild systems: 25 trees ⇒ 25 replicates per site. Total = 220 soil samples (500 g)

  Cropped olive: different modalities   irrigation : irrigated or not   exploitation : traditional or modern (high density)

  Nematode extraction from soil (Seinhorst, 1962)

  Counting and morphological identification (family / genus)

Results… PPN’s diversity

  Biodiversity indices:  Total number of nematodes N   Genus richness R   Local diversity (Shannon index H ')   Equitability: (E = H '/ ln (R) ) 

  Nematodes diversity in Moroccan olive systems: PPN and free-living nematodes.   PPN: 3 orders: Aphelenchida, Dorylaimida and Tylenchida

12 familles 28 genera

⇒  any significant effect of wild‐cropped olive and of cropping modali,es on PPN biodiversity indices 

Feral  High Density  Relictual  Wild  Tradidonal 

Equitability 

Source : IRD

Heterodera spp.  Pratylenchus spp.  Meloidogyne spp. Helicotylenchus spp.  Paratylenchus spp. 

Results … Abundance and Frequency of PPN

0 20 40 60 80 100

0 1

2 3

4 5

Frequency of PPN families in samples

Log

10 a

bund

ance

of P

PN

Aphelenchidae

Criconematidae

Heterodoridae

Hoplolaimidae

Longidoridae Meloidogynidae Paratylenchidae Pratylenchidae Rotylenchulidae

Telotylenchidae

Trichodoridae

Tylenchidae

Results… Community patterns

F2=11,22 % 

Aphelenchidae

Criconematidae

Heterodoridae

Hoplolaimidae

Longidoridae

Meloidogynidae

Paratylenchidae

Pratylenchidae Rotylenchulidae

Telotylenchidae

Trichodoridae

Tylenchidae

F1= 15

,72 % 

Results… Community patterns… in nature olive

M: Relictual (O. maroccana) S: Sauvage = wild

F: Feral

Results… Community patterns… nature vs cropped olive

N: Nature olive

C: Cropped olive

Results… Community patterns… in cropped olive

HD: High Density TI: Traditional Irrigated

TP: Traditional not Irrigated

Conclusion

  First report on PPN associated to olive in Morocco.   High diversity of PPN (12 families and 28 genera).   Presence of harmful taxa for agriculture as Pratylenchus spp. and

Meloidogyne spp. in all the olive systems.

  No significant effect of olive systems on PPN diversity in communities.   But significant effects on community patterns:

  Distinction between nature systems from cropped systems.   Favored presence of Heteroderidae and Longidoridae in nature

systems.   Enhancement of taxa (as Pratylenchus spp and Meloidogyne spp.) in

the cropped systems.   Favored presence of Meloidogyne spp. in irrigated conditions

⇒  Interactions between species in communities more involved than diversity?

 Other potential effects:   olive genotype?   soil factors?   associated plants?

Acknowledgements to…

  Pr. S. Al-Maghribi, all professors at Dept. Plant Protection, Tishreen University, Latakia, Syria.

  Dr. S. Bellafiore, IRD, UMR RPB, Montpellier, France.

  Dr. B. Facon, INRA, UMR CBGP, Montpellier, France.   Dr. E. Grenier, INRA, UMR IGEPP, Rennes, France.   Dr. M.L. Navas, SUPAGRO, UMR CEFE, Montpellier, France.

  Ministries of Higher Education in Syria and in France

Thank you for your attention